From 47b0e0ea72783c34d8422ebe776a70919ead0966 Mon Sep 17 00:00:00 2001
From: Pablo Montalvo <pablo.montalvo.leroux@gmail.com>
Date: Tue, 25 Nov 2025 10:53:23 +0100
Subject: [PATCH 01/25] one fix

---
 src/transformers/models/mistral/modeling_mistral.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/transformers/models/mistral/modeling_mistral.py b/src/transformers/models/mistral/modeling_mistral.py
index 60c7e2d49eed..b0b1738018e3 100644
--- a/src/transformers/models/mistral/modeling_mistral.py
+++ b/src/transformers/models/mistral/modeling_mistral.py
@@ -412,7 +412,7 @@ def forward(
 
 @auto_docstring
 class MistralForCausalLM(MistralPreTrainedModel, GenerationMixin):
-    _tied_weights_keys = {"lm_head.weight": "model.embed_tokens.weight"}
+    _tied_weights_keys = {}
     _tp_plan = {"lm_head": "colwise_rep"}
     _pp_plan = {"lm_head": (["hidden_states"], ["logits"])}
 

From 70fb4029d24522278ee938ca85fa70189a54e7b9 Mon Sep 17 00:00:00 2001
From: Pablo Montalvo <pablo.montalvo.leroux@gmail.com>
Date: Tue, 25 Nov 2025 11:59:12 +0100
Subject: [PATCH 02/25] attempt mistral3

---
 src/transformers/models/mistral/modular_mistral.py         | 2 +-
 src/transformers/models/mistral3/configuration_mistral3.py | 5 ++++-
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/transformers/models/mistral/modular_mistral.py b/src/transformers/models/mistral/modular_mistral.py
index 709ff855c399..e5f33487133b 100644
--- a/src/transformers/models/mistral/modular_mistral.py
+++ b/src/transformers/models/mistral/modular_mistral.py
@@ -174,7 +174,7 @@ def forward(
 
 
 class MistralForCausalLM(LlamaForCausalLM):
-    pass
+    _tied_weights_keys = {}
 
 
 class MistralForTokenClassification(LlamaForTokenClassification):
diff --git a/src/transformers/models/mistral3/configuration_mistral3.py b/src/transformers/models/mistral3/configuration_mistral3.py
index 59851c135987..2cbac8952fa0 100644
--- a/src/transformers/models/mistral3/configuration_mistral3.py
+++ b/src/transformers/models/mistral3/configuration_mistral3.py
@@ -110,7 +110,10 @@ def __init__(
 
         if isinstance(text_config, dict):
             text_config["model_type"] = text_config.get("model_type", "mistral")
-            text_config = CONFIG_MAPPING[text_config["model_type"]](**text_config)
+            text_config = CONFIG_MAPPING[text_config["model_type"]](
+                **text_config,
+                tie_word_embeddings=False
+                )
         elif text_config is None:
             text_config = CONFIG_MAPPING["mistral"](
                 attention_dropout=0.0,

From 6ce2bc66a356387081cadc8fe5cfbf414b9d2186 Mon Sep 17 00:00:00 2001
From: Pablo Montalvo <pablo.montalvo.leroux@gmail.com>
Date: Tue, 25 Nov 2025 13:43:37 +0100
Subject: [PATCH 03/25] empty dict

---
 src/transformers/models/mistral3/modeling_mistral3.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/transformers/models/mistral3/modeling_mistral3.py b/src/transformers/models/mistral3/modeling_mistral3.py
index 0f6e2a1d3efc..8fc7735be32f 100644
--- a/src/transformers/models/mistral3/modeling_mistral3.py
+++ b/src/transformers/models/mistral3/modeling_mistral3.py
@@ -360,7 +360,7 @@ class Mistral3ForConditionalGeneration(Mistral3PreTrainedModel, GenerationMixin)
         r"^multi_modal_projector": "model.multi_modal_projector",
         r"^language_model.lm_head": "lm_head",
     }
-    _tied_weights_keys = {"lm_head.weight": "model.language_model.embed_tokens.weight"}
+    _tied_weights_keys = {} # "lm_head.weight": "model.language_model.embed_tokens.weight"}
 
     def __init__(self, config: Mistral3Config):
         super().__init__(config)

From 60665c6981567762fe35895b5f36edd904a310c1 Mon Sep 17 00:00:00 2001
From: Pablo Montalvo <pablo.montalvo.leroux@gmail.com>
Date: Tue, 25 Nov 2025 15:18:41 +0100
Subject: [PATCH 04/25] that was olmoe's problem

---
 src/transformers/conversion_mapping.py | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/src/transformers/conversion_mapping.py b/src/transformers/conversion_mapping.py
index b6aad7e94650..f27abae657e6 100644
--- a/src/transformers/conversion_mapping.py
+++ b/src/transformers/conversion_mapping.py
@@ -117,6 +117,21 @@ def _build_checkpoint_conversion_mapping():
     mapping["qwen3_vl_moe"] = mapping["qwen2_moe"].copy()
     mapping["hunyuan_v1_moe"] = mapping["qwen2_moe"].copy()
     mapping["minimax"] = mapping["mixtral"].copy()
+    mapping["olmoe"] = [
+            WeightConverter(
+                source_keys=[
+                    "mlp.experts.*.gate_proj.weight",
+                    "mlp.experts.*.up_proj.weight",
+                ],
+                target_keys="mlp.experts.gate_up_proj",
+                operations=[MergeModulelist(dim=0), Concatenate(dim=1)],
+            ),
+            WeightConverter(
+                source_keys=["mlp.experts.*.down_proj.weight"],
+                target_keys="mlp.experts.down_proj",
+                operations=[MergeModulelist(dim=0)],
+            ),
+        ]
 
     return mapping
 

From aa7ab8039c6baeeec6f32ff415dc591c090bb0de Mon Sep 17 00:00:00 2001
From: Pablo Montalvo <pablo.montalvo.leroux@gmail.com>
Date: Tue, 25 Nov 2025 16:54:03 +0100
Subject: [PATCH 05/25] current CI status?

---
 src/transformers/conversion_mapping.py        | 28 +++++++++----------
 .../models/mistral/modeling_mistral.py        |  2 +-
 .../models/mistral/modular_mistral.py         |  2 +-
 .../models/mistral3/configuration_mistral3.py |  5 +---
 .../models/mistral3/modeling_mistral3.py      |  2 +-
 5 files changed, 18 insertions(+), 21 deletions(-)

diff --git a/src/transformers/conversion_mapping.py b/src/transformers/conversion_mapping.py
index f27abae657e6..735291c50d9f 100644
--- a/src/transformers/conversion_mapping.py
+++ b/src/transformers/conversion_mapping.py
@@ -118,20 +118,20 @@ def _build_checkpoint_conversion_mapping():
     mapping["hunyuan_v1_moe"] = mapping["qwen2_moe"].copy()
     mapping["minimax"] = mapping["mixtral"].copy()
     mapping["olmoe"] = [
-            WeightConverter(
-                source_keys=[
-                    "mlp.experts.*.gate_proj.weight",
-                    "mlp.experts.*.up_proj.weight",
-                ],
-                target_keys="mlp.experts.gate_up_proj",
-                operations=[MergeModulelist(dim=0), Concatenate(dim=1)],
-            ),
-            WeightConverter(
-                source_keys=["mlp.experts.*.down_proj.weight"],
-                target_keys="mlp.experts.down_proj",
-                operations=[MergeModulelist(dim=0)],
-            ),
-        ]
+        WeightConverter(
+            source_keys=[
+                "mlp.experts.*.gate_proj.weight",
+                "mlp.experts.*.up_proj.weight",
+            ],
+            target_keys="mlp.experts.gate_up_proj",
+            operations=[MergeModulelist(dim=0), Concatenate(dim=1)],
+        ),
+        WeightConverter(
+            source_keys=["mlp.experts.*.down_proj.weight"],
+            target_keys="mlp.experts.down_proj",
+            operations=[MergeModulelist(dim=0)],
+        ),
+    ]
 
     return mapping
 
diff --git a/src/transformers/models/mistral/modeling_mistral.py b/src/transformers/models/mistral/modeling_mistral.py
index b0b1738018e3..60c7e2d49eed 100644
--- a/src/transformers/models/mistral/modeling_mistral.py
+++ b/src/transformers/models/mistral/modeling_mistral.py
@@ -412,7 +412,7 @@ def forward(
 
 @auto_docstring
 class MistralForCausalLM(MistralPreTrainedModel, GenerationMixin):
-    _tied_weights_keys = {}
+    _tied_weights_keys = {"lm_head.weight": "model.embed_tokens.weight"}
     _tp_plan = {"lm_head": "colwise_rep"}
     _pp_plan = {"lm_head": (["hidden_states"], ["logits"])}
 
diff --git a/src/transformers/models/mistral/modular_mistral.py b/src/transformers/models/mistral/modular_mistral.py
index e5f33487133b..709ff855c399 100644
--- a/src/transformers/models/mistral/modular_mistral.py
+++ b/src/transformers/models/mistral/modular_mistral.py
@@ -174,7 +174,7 @@ def forward(
 
 
 class MistralForCausalLM(LlamaForCausalLM):
-    _tied_weights_keys = {}
+    pass
 
 
 class MistralForTokenClassification(LlamaForTokenClassification):
diff --git a/src/transformers/models/mistral3/configuration_mistral3.py b/src/transformers/models/mistral3/configuration_mistral3.py
index 2cbac8952fa0..80e6a91bf22c 100644
--- a/src/transformers/models/mistral3/configuration_mistral3.py
+++ b/src/transformers/models/mistral3/configuration_mistral3.py
@@ -110,10 +110,7 @@ def __init__(
 
         if isinstance(text_config, dict):
             text_config["model_type"] = text_config.get("model_type", "mistral")
-            text_config = CONFIG_MAPPING[text_config["model_type"]](
-                **text_config,
-                tie_word_embeddings=False
-                )
+            text_config = CONFIG_MAPPING[text_config["model_type"]](**text_config, tie_word_embeddings=False)
         elif text_config is None:
             text_config = CONFIG_MAPPING["mistral"](
                 attention_dropout=0.0,
diff --git a/src/transformers/models/mistral3/modeling_mistral3.py b/src/transformers/models/mistral3/modeling_mistral3.py
index 8fc7735be32f..0f6e2a1d3efc 100644
--- a/src/transformers/models/mistral3/modeling_mistral3.py
+++ b/src/transformers/models/mistral3/modeling_mistral3.py
@@ -360,7 +360,7 @@ class Mistral3ForConditionalGeneration(Mistral3PreTrainedModel, GenerationMixin)
         r"^multi_modal_projector": "model.multi_modal_projector",
         r"^language_model.lm_head": "lm_head",
     }
-    _tied_weights_keys = {} # "lm_head.weight": "model.language_model.embed_tokens.weight"}
+    _tied_weights_keys = {"lm_head.weight": "model.language_model.embed_tokens.weight"}
 
     def __init__(self, config: Mistral3Config):
         super().__init__(config)

From afa33c5d0e279de74e8d8aedf4b0dac90da7b96a Mon Sep 17 00:00:00 2001
From: Pablo Montalvo <pablo.montalvo.leroux@gmail.com>
Date: Tue, 25 Nov 2025 16:55:12 +0100
Subject: [PATCH 06/25] actual CI status

---
 src/transformers/models/mistral3/configuration_mistral3.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/transformers/models/mistral3/configuration_mistral3.py b/src/transformers/models/mistral3/configuration_mistral3.py
index 80e6a91bf22c..59851c135987 100644
--- a/src/transformers/models/mistral3/configuration_mistral3.py
+++ b/src/transformers/models/mistral3/configuration_mistral3.py
@@ -110,7 +110,7 @@ def __init__(
 
         if isinstance(text_config, dict):
             text_config["model_type"] = text_config.get("model_type", "mistral")
-            text_config = CONFIG_MAPPING[text_config["model_type"]](**text_config, tie_word_embeddings=False)
+            text_config = CONFIG_MAPPING[text_config["model_type"]](**text_config)
         elif text_config is None:
             text_config = CONFIG_MAPPING["mistral"](
                 attention_dropout=0.0,

From 22a258f6baa33f2588e7071fd9156dbb7093a669 Mon Sep 17 00:00:00 2001
From: Pablo Montalvo <pablo.montalvo.leroux@gmail.com>
Date: Tue, 25 Nov 2025 17:17:25 +0100
Subject: [PATCH 07/25] simplify

---
 src/transformers/conversion_mapping.py | 16 +---------------
 1 file changed, 1 insertion(+), 15 deletions(-)

diff --git a/src/transformers/conversion_mapping.py b/src/transformers/conversion_mapping.py
index 735291c50d9f..10375807422a 100644
--- a/src/transformers/conversion_mapping.py
+++ b/src/transformers/conversion_mapping.py
@@ -116,22 +116,8 @@ def _build_checkpoint_conversion_mapping():
     mapping["qwen3_next"] = mapping["qwen2_moe"].copy()
     mapping["qwen3_vl_moe"] = mapping["qwen2_moe"].copy()
     mapping["hunyuan_v1_moe"] = mapping["qwen2_moe"].copy()
+    mapping["olmoe"] = mapping["qwen2_moe"].copy()
     mapping["minimax"] = mapping["mixtral"].copy()
-    mapping["olmoe"] = [
-        WeightConverter(
-            source_keys=[
-                "mlp.experts.*.gate_proj.weight",
-                "mlp.experts.*.up_proj.weight",
-            ],
-            target_keys="mlp.experts.gate_up_proj",
-            operations=[MergeModulelist(dim=0), Concatenate(dim=1)],
-        ),
-        WeightConverter(
-            source_keys=["mlp.experts.*.down_proj.weight"],
-            target_keys="mlp.experts.down_proj",
-            operations=[MergeModulelist(dim=0)],
-        ),
-    ]
 
     return mapping
 

From 076f20ed6096c136b095aeae65a726dac0bed25c Mon Sep 17 00:00:00 2001
From: Pablo <pablo.montalvo.leroux@gmail.com>
Date: Tue, 25 Nov 2025 17:56:52 +0100
Subject: [PATCH 08/25] hmm?

---
 src/transformers/modeling_utils.py | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/transformers/modeling_utils.py b/src/transformers/modeling_utils.py
index 748d7af639af..bac9fe1c5085 100644
--- a/src/transformers/modeling_utils.py
+++ b/src/transformers/modeling_utils.py
@@ -2248,8 +2248,10 @@ def get_expanded_tied_weights_keys(self, all_submodels: bool = False) -> dict:
             return expanded_tied_weights
 
         tied_mapping = self._tied_weights_keys
+        text_config = self.config.get_text_config(decoder=True)
+        tie_word_embeddings = getattr(text_config, "tie_word_embeddings", self.config.tie_word_embeddings)
         # If the config does not specify any tying, return empty dict
-        if not self.config.tie_word_embeddings and not self.config.tie_encoder_decoder:
+        if not tie_word_embeddings and not self.config.tie_encoder_decoder:
             return {}
         # If None, return empty dict
         elif tied_mapping is None:
@@ -3174,7 +3176,7 @@ def save_pretrained(
             shared_ptrs = {ptr: names for ptr, names in ptrs.items() if len(names) > 1}
 
             # Recursively descend to find tied weight keys
-            _tied_weights_keys = set(_get_tied_weight_keys(self))
+            _tied_weights_keys = set(self.all_tied_weights_keys.keys())
             error_names = []
             to_delete_names = set()
             for names in shared_ptrs.values():

From 58ec6e632c153bc4acdfaa345e3dfdb58a0c1773 Mon Sep 17 00:00:00 2001
From: Pablo <pablo.montalvo.leroux@gmail.com>
Date: Tue, 25 Nov 2025 18:14:14 +0100
Subject: [PATCH 09/25] bird

---
 src/transformers/modeling_utils.py | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/src/transformers/modeling_utils.py b/src/transformers/modeling_utils.py
index bac9fe1c5085..51f9c801377f 100644
--- a/src/transformers/modeling_utils.py
+++ b/src/transformers/modeling_utils.py
@@ -3176,7 +3176,11 @@ def save_pretrained(
             shared_ptrs = {ptr: names for ptr, names in ptrs.items() if len(names) > 1}
 
             # Recursively descend to find tied weight keys
-            _tied_weights_keys = set(self.all_tied_weights_keys.keys())
+            tied_keys_attr = getattr(self, "all_tied_weights_keys", None)
+            if tied_keys_attr is not None:
+                _tied_weights_keys = set(tied_keys_attr.keys())
+            else:
+                _tied_weights_keys = set(_get_tied_weight_keys(self))
             error_names = []
             to_delete_names = set()
             for names in shared_ptrs.values():
@@ -4410,7 +4414,9 @@ def _move_missing_keys_from_meta_to_cpu(
         # The tied weight keys are in the "missing" usually, but they should not be moved (they will be tied anyway)
         # This is especially important because if they are moved, they will lose the `_is_hf_initialized` flag, and they
         # will be re-initialized for nothing (which can be quite long)
-        for key in missing_keys - self.all_tied_weights_keys.keys():
+        tied_keys_attr = getattr(self, "all_tied_weights_keys", {}) or {}
+        tied_keys = set(tied_keys_attr.keys())
+        for key in missing_keys - tied_keys:
             param = model_state_dict[key]
             # Buffers are not initialized on the meta device, so we still need this check to avoid overwriting them
             if param.device == torch.device("meta"):

From 5a05c977749d8bb3996eff5866468639694c5a09 Mon Sep 17 00:00:00 2001
From: Pablo Montalvo <pablo.montalvo.leroux@gmail.com>
Date: Tue, 25 Nov 2025 22:36:15 +0100
Subject: [PATCH 10/25] force tie word embeddings to false

---
 src/transformers/configuration_utils.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/transformers/configuration_utils.py b/src/transformers/configuration_utils.py
index 5d6fbda009dc..81eec8c688a0 100755
--- a/src/transformers/configuration_utils.py
+++ b/src/transformers/configuration_utils.py
@@ -755,6 +755,10 @@ def from_dict(
 
         config = cls(**config_dict)
 
+        # default tie_word_embeddings to False if None, see https://github.com/huggingface/transformers/issues/42313
+        if hasattr(config, 'tie_word_embeddings') and config.tie_word_embeddings is None:
+            config.tie_word_embeddings = False
+
         # Update config with kwargs if needed
         if "num_labels" in kwargs and "id2label" in kwargs:
             num_labels = kwargs["num_labels"]

From 9c81dfcfd951ecfb06bfb4a16ac94ae156dfa1a4 Mon Sep 17 00:00:00 2001
From: Pablo Montalvo <pablo.montalvo.leroux@gmail.com>
Date: Tue, 25 Nov 2025 22:58:16 +0100
Subject: [PATCH 11/25] specifics of FSMT

---
 src/transformers/configuration_utils.py            | 2 +-
 src/transformers/models/fsmt/configuration_fsmt.py | 1 +
 tests/models/fsmt/test_modeling_fsmt.py            | 3 +++
 3 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/transformers/configuration_utils.py b/src/transformers/configuration_utils.py
index 81eec8c688a0..212a4f4626cd 100755
--- a/src/transformers/configuration_utils.py
+++ b/src/transformers/configuration_utils.py
@@ -756,7 +756,7 @@ def from_dict(
         config = cls(**config_dict)
 
         # default tie_word_embeddings to False if None, see https://github.com/huggingface/transformers/issues/42313
-        if hasattr(config, 'tie_word_embeddings') and config.tie_word_embeddings is None:
+        if hasattr(config, "tie_word_embeddings") and config.tie_word_embeddings is None:
             config.tie_word_embeddings = False
 
         # Update config with kwargs if needed
diff --git a/src/transformers/models/fsmt/configuration_fsmt.py b/src/transformers/models/fsmt/configuration_fsmt.py
index a1075016c3f4..fc68464f252f 100644
--- a/src/transformers/models/fsmt/configuration_fsmt.py
+++ b/src/transformers/models/fsmt/configuration_fsmt.py
@@ -194,6 +194,7 @@ def __init__(
             bos_token_id=eos_token_id,
             is_encoder_decoder=is_encoder_decoder,
             num_hidden_layers=encoder_layers,
+            tie_word_embeddings=tie_word_embeddings,
         )
         if "decoder" in common_kwargs:
             del common_kwargs["decoder"]
diff --git a/tests/models/fsmt/test_modeling_fsmt.py b/tests/models/fsmt/test_modeling_fsmt.py
index acc29cac7ec0..d14c6b3225a2 100644
--- a/tests/models/fsmt/test_modeling_fsmt.py
+++ b/tests/models/fsmt/test_modeling_fsmt.py
@@ -125,6 +125,7 @@ def get_config(self):
             eos_token_id=self.eos_token_id,
             bos_token_id=self.bos_token_id,
             pad_token_id=self.pad_token_id,
+            tie_word_embeddings=True,
         )
 
     def prepare_config_and_inputs_for_common(self):
@@ -254,6 +255,7 @@ def test_ensure_weights_are_shared(self):
         config, inputs_dict = self.model_tester.prepare_config_and_inputs()
 
         config.tie_word_embeddings = True
+        config.decoder.tie_word_embeddings = True
         model = FSMTForConditionalGeneration(config)
 
         # FSMT shares three weights.
@@ -270,6 +272,7 @@ def test_ensure_weights_are_shared(self):
         )
 
         config.tie_word_embeddings = False
+        config.decoder.tie_word_embeddings = False
         model = FSMTForConditionalGeneration(config)
 
         # FSMT shares three weights.

From e22acad60fcbc349ea6558ba5f681d5d3abcc63c Mon Sep 17 00:00:00 2001
From: Pablo Montalvo <pablo.montalvo.leroux@gmail.com>
Date: Wed, 26 Nov 2025 14:20:59 +0100
Subject: [PATCH 12/25] wrong reference?

---
 src/transformers/core_model_loading.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/transformers/core_model_loading.py b/src/transformers/core_model_loading.py
index 983ae97cbdc5..80c90e538b27 100644
--- a/src/transformers/core_model_loading.py
+++ b/src/transformers/core_model_loading.py
@@ -504,7 +504,7 @@ def set_param_for_module(
             missing_keys.discard(target_name)
             if ref is not None and ref.shape != param_value.shape and hf_quantizer is None:
                 mismatch_keys.add((target_name, param_value.shape, ref.shape))
-                module_obj.param_name._is_hf_initialized = False  # Needs to be initialized
+                ref._is_hf_initialized = False  # unsure - but seems unreachable else?
             else:
                 # super important otherwise _init_weight will re-init the param
                 param_value._is_hf_initialized = True

From f939769ebe29c2863ca39be2b61357c94284bd3a Mon Sep 17 00:00:00 2001
From: Pablo Montalvo <pablo.montalvo.leroux@gmail.com>
Date: Thu, 27 Nov 2025 16:44:13 +0100
Subject: [PATCH 13/25] finalize

---
 src/transformers/core_model_loading.py |  1 -
 src/transformers/modeling_utils.py     |  7 +++-
 tests/test_modeling_common.py          | 45 ++++++++++++++++++++++++++
 3 files changed, 51 insertions(+), 2 deletions(-)

diff --git a/src/transformers/core_model_loading.py b/src/transformers/core_model_loading.py
index 80c90e538b27..9411402a7def 100644
--- a/src/transformers/core_model_loading.py
+++ b/src/transformers/core_model_loading.py
@@ -504,7 +504,6 @@ def set_param_for_module(
             missing_keys.discard(target_name)
             if ref is not None and ref.shape != param_value.shape and hf_quantizer is None:
                 mismatch_keys.add((target_name, param_value.shape, ref.shape))
-                ref._is_hf_initialized = False  # unsure - but seems unreachable else?
             else:
                 # super important otherwise _init_weight will re-init the param
                 param_value._is_hf_initialized = True
diff --git a/src/transformers/modeling_utils.py b/src/transformers/modeling_utils.py
index 51f9c801377f..9ead247e6431 100644
--- a/src/transformers/modeling_utils.py
+++ b/src/transformers/modeling_utils.py
@@ -2249,7 +2249,12 @@ def get_expanded_tied_weights_keys(self, all_submodels: bool = False) -> dict:
 
         tied_mapping = self._tied_weights_keys
         text_config = self.config.get_text_config(decoder=True)
-        tie_word_embeddings = getattr(text_config, "tie_word_embeddings", self.config.tie_word_embeddings)
+        if not hasattr(text_config, "tie_word_embeddings"):
+            logger.warning(
+                f"Text config {text_config.__class__.__name__} does not have 'tie_word_embeddings' attribute. "
+                "This may cause issues with weight tying."
+            )
+        tie_word_embeddings = text_config.tie_word_embeddings
         # If the config does not specify any tying, return empty dict
         if not tie_word_embeddings and not self.config.tie_encoder_decoder:
             return {}
diff --git a/tests/test_modeling_common.py b/tests/test_modeling_common.py
index 66a6dfd12653..76f3d6398d82 100755
--- a/tests/test_modeling_common.py
+++ b/tests/test_modeling_common.py
@@ -2100,6 +2100,51 @@ def test_tied_weights_keys(self):
                 f"Missing `_tied_weights_keys` for {model_class}: add all of {tied_params} except one.",
             )
 
+    def test_tie_word_embeddings_is_authoritative(self):
+        original_config, _ = self.model_tester.prepare_config_and_inputs_for_common()
+
+        for model_class in self.all_model_classes:
+            tied_config = copy.deepcopy(original_config)
+            tied_config.get_text_config().tie_word_embeddings = True
+            tied_config.tie_word_embeddings = True
+
+            untied_config = copy.deepcopy(original_config)
+            untied_config.get_text_config().tie_word_embeddings = False
+            untied_config.tie_word_embeddings = False
+
+            model_tied = model_class(tied_config)
+            model_untied = model_class(untied_config)
+
+            if not hasattr(model_tied, "_tied_weights_keys") or not model_tied._tied_weights_keys:
+                continue
+
+            tied_keys = model_tied._tied_weights_keys
+            state_dict_tied = model_tied.state_dict()
+            state_dict_untied = model_untied.state_dict()
+
+            for target_key, source_key in tied_keys.items():
+                if target_key not in state_dict_tied or source_key not in state_dict_tied:
+                    continue
+                if target_key not in state_dict_untied or source_key not in state_dict_untied:
+                    continue
+
+                target_tied_ptr = id_tensor_storage(state_dict_tied[target_key])
+                source_tied_ptr = id_tensor_storage(state_dict_tied[source_key])
+                target_untied_ptr = id_tensor_storage(state_dict_untied[target_key])
+                source_untied_ptr = id_tensor_storage(state_dict_untied[source_key])
+
+                self.assertEqual(
+                    target_tied_ptr,
+                    source_tied_ptr,
+                    f"{model_class}: With tie_word_embeddings=True, '{target_key}' should share storage with '{source_key}'",
+                )
+                self.assertNotEqual(
+                    target_untied_ptr,
+                    source_untied_ptr,
+                    f"{model_class}: With tie_word_embeddings=False, '{target_key}' should NOT share storage with '{source_key}'. "
+                    f"Config tie_word_embeddings must be authoritative over class-level _tied_weights_keys.",
+                )
+
     def test_model_weights_reload_no_missing_tied_weights(self):
         for model_class in self.all_model_classes:
             config, _ = self.model_tester.prepare_config_and_inputs_for_common()

From 9960aa2e3256a75081b336bc1165b757a8f3234a Mon Sep 17 00:00:00 2001
From: Pablo Montalvo <pablo.montalvo.leroux@gmail.com>
Date: Thu, 27 Nov 2025 16:51:45 +0100
Subject: [PATCH 14/25] fixup

---
 tests/test_modeling_common.py | 2 --
 1 file changed, 2 deletions(-)

diff --git a/tests/test_modeling_common.py b/tests/test_modeling_common.py
index 76f3d6398d82..838e1addcbcb 100755
--- a/tests/test_modeling_common.py
+++ b/tests/test_modeling_common.py
@@ -2106,11 +2106,9 @@ def test_tie_word_embeddings_is_authoritative(self):
         for model_class in self.all_model_classes:
             tied_config = copy.deepcopy(original_config)
             tied_config.get_text_config().tie_word_embeddings = True
-            tied_config.tie_word_embeddings = True
 
             untied_config = copy.deepcopy(original_config)
             untied_config.get_text_config().tie_word_embeddings = False
-            untied_config.tie_word_embeddings = False
 
             model_tied = model_class(tied_config)
             model_untied = model_class(untied_config)

From 24f0b0992adb1c8aa21ed14b831513596997554a Mon Sep 17 00:00:00 2001
From: Pablo Montalvo <pablo.montalvo.leroux@gmail.com>
Date: Thu, 27 Nov 2025 17:36:41 +0100
Subject: [PATCH 15/25] weird mamba error

---
 src/transformers/integrations/hub_kernels.py | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/transformers/integrations/hub_kernels.py b/src/transformers/integrations/hub_kernels.py
index 0ab866ecbd6d..76f2333c5955 100644
--- a/src/transformers/integrations/hub_kernels.py
+++ b/src/transformers/integrations/hub_kernels.py
@@ -288,6 +288,12 @@ def lazy_load_kernel(kernel_name: str, mapping: dict[str, ModuleType | None] = _
             mapping[kernel_name] = kernel
         except FileNotFoundError:
             mapping[kernel_name] = None
+        except AssertionError as error:
+            logger.warning_once(
+                f"Failed to load the '{kernel_name}' kernel from '{repo_id}' because the current environment does not "
+                f"support the required backend: {error}"
+            )
+            mapping[kernel_name] = None
 
     else:
         # Try to import is_{kernel_name}_available from ..utils

From d2a03d2a3d2857883e1fcc34476d9b03c6c18e84 Mon Sep 17 00:00:00 2001
From: Pablo Montalvo <pablo.montalvo.leroux@gmail.com>
Date: Thu, 27 Nov 2025 17:37:28 +0100
Subject: [PATCH 16/25] fix tied weights

---
 .../kyutai_speech_to_text/modeling_kyutai_speech_to_text.py     | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/transformers/models/kyutai_speech_to_text/modeling_kyutai_speech_to_text.py b/src/transformers/models/kyutai_speech_to_text/modeling_kyutai_speech_to_text.py
index 1e95b92d528d..5b0c3497ad76 100644
--- a/src/transformers/models/kyutai_speech_to_text/modeling_kyutai_speech_to_text.py
+++ b/src/transformers/models/kyutai_speech_to_text/modeling_kyutai_speech_to_text.py
@@ -1069,7 +1069,7 @@ def _prepare_4d_causal_attention_mask_with_cache_position(
 
 @auto_docstring
 class KyutaiSpeechToTextForConditionalGeneration(KyutaiSpeechToTextPreTrainedModel, GenerationMixin):
-    _tied_weights_keys = {"lm_head.weight": "model.embed_tokens.weight"}
+    _tied_weights_keys = {"lm_head.weight": "model.embed_tokens.embed_tokens.weight"}
     _tp_plan = {"lm_head": "colwise_rep"}
     _pp_plan = {"lm_head": (["hidden_states"], ["logits"])}
     _keep_in_fp32_modules_strict = ["codec_model"]

From 8c4fb33714916d4a6c3bb64070dca35fbd063193 Mon Sep 17 00:00:00 2001
From: Pablo Montalvo <pablo.montalvo.leroux@gmail.com>
Date: Thu, 27 Nov 2025 17:37:42 +0100
Subject: [PATCH 17/25] hack musicgen

---
 src/transformers/models/musicgen/configuration_musicgen.py  | 6 ++++++
 .../models/musicgen_melody/configuration_musicgen_melody.py | 6 ++++++
 2 files changed, 12 insertions(+)

diff --git a/src/transformers/models/musicgen/configuration_musicgen.py b/src/transformers/models/musicgen/configuration_musicgen.py
index 76c951668f46..bff720e5cfe2 100644
--- a/src/transformers/models/musicgen/configuration_musicgen.py
+++ b/src/transformers/models/musicgen/configuration_musicgen.py
@@ -221,5 +221,11 @@ def __init__(self, text_encoder, audio_encoder, decoder, **kwargs):
     def sampling_rate(self):
         return self.audio_encoder.sampling_rate
 
+    # overriding these because they crash - not 100% sure of that one
+    def get_text_config(self, decoder=None, encoder=None):
+        if decoder is None and encoder is None:
+            decoder = True
+        return super().get_text_config(decoder=decoder, encoder=encoder)
+
 
 __all__ = ["MusicgenConfig", "MusicgenDecoderConfig"]
diff --git a/src/transformers/models/musicgen_melody/configuration_musicgen_melody.py b/src/transformers/models/musicgen_melody/configuration_musicgen_melody.py
index a4ec8528590a..af184b241408 100644
--- a/src/transformers/models/musicgen_melody/configuration_musicgen_melody.py
+++ b/src/transformers/models/musicgen_melody/configuration_musicgen_melody.py
@@ -234,5 +234,11 @@ def __init__(
     def sampling_rate(self):
         return self.audio_encoder.sampling_rate
 
+    # overriding these because they crash - not 100% sure of that one
+    def get_text_config(self, decoder=None, encoder=None):
+        if decoder is None and encoder is None:
+            decoder = True
+        return super().get_text_config(decoder=decoder, encoder=encoder)
+
 
 __all__ = ["MusicgenMelodyConfig", "MusicgenMelodyDecoderConfig"]

From c8d8ad06b57ebf1bd57f11c339c63a4f4aadb11e Mon Sep 17 00:00:00 2001
From: Pablo Montalvo <pablo.montalvo.leroux@gmail.com>
Date: Thu, 27 Nov 2025 17:41:11 +0100
Subject: [PATCH 18/25] tie_encoder_decoder workaround

---
 src/transformers/modeling_utils.py | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/transformers/modeling_utils.py b/src/transformers/modeling_utils.py
index 9ead247e6431..26db03c27fae 100644
--- a/src/transformers/modeling_utils.py
+++ b/src/transformers/modeling_utils.py
@@ -2254,9 +2254,11 @@ def get_expanded_tied_weights_keys(self, all_submodels: bool = False) -> dict:
                 f"Text config {text_config.__class__.__name__} does not have 'tie_word_embeddings' attribute. "
                 "This may cause issues with weight tying."
             )
-        tie_word_embeddings = text_config.tie_word_embeddings
+        tie_word_embeddings = getattr(text_config, "tie_word_embeddings", None)
+        tie_encoder_decoder = getattr(self.config, "tie_encoder_decoder", False)
+        should_tie = tie_encoder_decoder if tie_word_embeddings is None else tie_word_embeddings
         # If the config does not specify any tying, return empty dict
-        if not tie_word_embeddings and not self.config.tie_encoder_decoder:
+        if not should_tie:
             return {}
         # If None, return empty dict
         elif tied_mapping is None:

From 65dca34d03ba82d3f861204f3ad09dde01d2e019 Mon Sep 17 00:00:00 2001
From: Cyril Vallez <cyril.vallez@gmail.com>
Date: Mon, 1 Dec 2025 16:38:17 +0100
Subject: [PATCH 19/25] revert unwanted changes

---
 src/transformers/configuration_utils.py |  4 ----
 src/transformers/conversion_mapping.py  |  1 -
 src/transformers/modeling_utils.py      | 21 +++------------------
 3 files changed, 3 insertions(+), 23 deletions(-)

diff --git a/src/transformers/configuration_utils.py b/src/transformers/configuration_utils.py
index c08df46a665d..53d6a8a900a8 100755
--- a/src/transformers/configuration_utils.py
+++ b/src/transformers/configuration_utils.py
@@ -751,10 +751,6 @@ def from_dict(
 
         config = cls(**config_dict)
 
-        # default tie_word_embeddings to False if None, see https://github.com/huggingface/transformers/issues/42313
-        if hasattr(config, "tie_word_embeddings") and config.tie_word_embeddings is None:
-            config.tie_word_embeddings = False
-
         # Update config with kwargs if needed
         if "num_labels" in kwargs and "id2label" in kwargs:
             num_labels = kwargs["num_labels"]
diff --git a/src/transformers/conversion_mapping.py b/src/transformers/conversion_mapping.py
index 10375807422a..b6aad7e94650 100644
--- a/src/transformers/conversion_mapping.py
+++ b/src/transformers/conversion_mapping.py
@@ -116,7 +116,6 @@ def _build_checkpoint_conversion_mapping():
     mapping["qwen3_next"] = mapping["qwen2_moe"].copy()
     mapping["qwen3_vl_moe"] = mapping["qwen2_moe"].copy()
     mapping["hunyuan_v1_moe"] = mapping["qwen2_moe"].copy()
-    mapping["olmoe"] = mapping["qwen2_moe"].copy()
     mapping["minimax"] = mapping["mixtral"].copy()
 
     return mapping
diff --git a/src/transformers/modeling_utils.py b/src/transformers/modeling_utils.py
index 75d4c42ccf14..403f5f6eb295 100644
--- a/src/transformers/modeling_utils.py
+++ b/src/transformers/modeling_utils.py
@@ -2254,17 +2254,8 @@ def get_expanded_tied_weights_keys(self, all_submodels: bool = False) -> dict:
             return expanded_tied_weights
 
         tied_mapping = self._tied_weights_keys
-        text_config = self.config.get_text_config(decoder=True)
-        if not hasattr(text_config, "tie_word_embeddings"):
-            logger.warning(
-                f"Text config {text_config.__class__.__name__} does not have 'tie_word_embeddings' attribute. "
-                "This may cause issues with weight tying."
-            )
-        tie_word_embeddings = getattr(text_config, "tie_word_embeddings", None)
-        tie_encoder_decoder = getattr(self.config, "tie_encoder_decoder", False)
-        should_tie = tie_encoder_decoder if tie_word_embeddings is None else tie_word_embeddings
         # If the config does not specify any tying, return empty dict
-        if not should_tie:
+        if not self.config.tie_word_embeddings and not self.config.tie_encoder_decoder:
             return {}
         # If None, return empty dict
         elif tied_mapping is None:
@@ -3187,11 +3178,7 @@ def save_pretrained(
             shared_ptrs = {ptr: names for ptr, names in ptrs.items() if len(names) > 1}
 
             # Recursively descend to find tied weight keys
-            tied_keys_attr = getattr(self, "all_tied_weights_keys", None)
-            if tied_keys_attr is not None:
-                _tied_weights_keys = set(tied_keys_attr.keys())
-            else:
-                _tied_weights_keys = set(_get_tied_weight_keys(self))
+            _tied_weights_keys = set(_get_tied_weight_keys(self))
             error_names = []
             to_delete_names = set()
             for names in shared_ptrs.values():
@@ -4423,9 +4410,7 @@ def _move_missing_keys_from_meta_to_cpu(
         # The tied weight keys are in the "missing" usually, but they should not be moved (they will be tied anyway)
         # This is especially important because if they are moved, they will lose the `_is_hf_initialized` flag, and they
         # will be re-initialized for nothing (which can be quite long)
-        tied_keys_attr = getattr(self, "all_tied_weights_keys", {}) or {}
-        tied_keys = set(tied_keys_attr.keys())
-        for key in missing_keys - tied_keys:
+        for key in missing_keys - self.all_tied_weights_keys.keys():
             param = model_state_dict[key]
             # Buffers are not initialized on the meta device, so we still need this check to avoid overwriting them
             if param.device == torch.device("meta"):

From f85d0f4f44c954de5c5a1ced268c67cb9ee7507c Mon Sep 17 00:00:00 2001
From: Cyril Vallez <cyril.vallez@gmail.com>
Date: Mon, 1 Dec 2025 16:47:47 +0100
Subject: [PATCH 20/25] hardcode llava onevision

---
 .../llava_onevision/configuration_llava_onevision.py     | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/transformers/models/llava_onevision/configuration_llava_onevision.py b/src/transformers/models/llava_onevision/configuration_llava_onevision.py
index 9fd1e850f0e5..d9f35dc7dc28 100644
--- a/src/transformers/models/llava_onevision/configuration_llava_onevision.py
+++ b/src/transformers/models/llava_onevision/configuration_llava_onevision.py
@@ -102,7 +102,6 @@ def __init__(
         vision_feature_layer=-1,
         vision_aspect_ratio="anyres_max_9",
         image_grid_pinpoints=None,
-        tie_word_embeddings=False,
         multimodal_projector_bias=True,
         **kwargs,
     ):
@@ -188,7 +187,13 @@ def __init__(
 
         self.text_config = text_config
 
-        super().__init__(tie_word_embeddings=tie_word_embeddings, **kwargs)
+        super().__init__(**kwargs)
+
+        # Due to a mismatch at model addition-time, the `tie_word_embeddings` was saved in the text config, even
+        # though it concerns the main model... So we hardcode a fix here
+        if not self.tie_word_embeddings and self.text_config.tie_word_embeddings:
+            self.tie_word_embeddings = True
+            self.text_config.tie_word_embeddings = False
 
 
 __all__ = ["LlavaOnevisionConfig"]

From b5537a3930c32c1806e759712027fceb392d1ab3 Mon Sep 17 00:00:00 2001
From: Cyril Vallez <cyril.vallez@gmail.com>
Date: Mon, 1 Dec 2025 16:58:39 +0100
Subject: [PATCH 21/25] more

---
 .../llava_next_video/configuration_llava_next_video.py   | 9 +++++++--
 .../llava_onevision/configuration_llava_onevision.py     | 2 +-
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/src/transformers/models/llava_next_video/configuration_llava_next_video.py b/src/transformers/models/llava_next_video/configuration_llava_next_video.py
index 7b82b5ac5b89..86dec22c8e5b 100644
--- a/src/transformers/models/llava_next_video/configuration_llava_next_video.py
+++ b/src/transformers/models/llava_next_video/configuration_llava_next_video.py
@@ -103,7 +103,6 @@ def __init__(
         vision_feature_select_strategy="default",
         vision_feature_layer=-2,
         image_grid_pinpoints=None,
-        tie_word_embeddings=False,
         video_token_index=32000,
         spatial_pool_mode="average",
         spatial_pool_stride=2,
@@ -160,7 +159,13 @@ def __init__(
 
         self.text_config = text_config
 
-        super().__init__(tie_word_embeddings=tie_word_embeddings, **kwargs)
+        super().__init__(**kwargs)
+
+        # Due to a mismatch at model addition-time, the `tie_word_embeddings` was saved in the text config, even
+        # though it concerns the main model, while it was set to False by default in the main model... So we hardcode a fix here
+        if not self.tie_word_embeddings and self.text_config.tie_word_embeddings:
+            self.tie_word_embeddings = True
+            self.text_config.tie_word_embeddings = False
 
 
 __all__ = ["LlavaNextVideoConfig"]
diff --git a/src/transformers/models/llava_onevision/configuration_llava_onevision.py b/src/transformers/models/llava_onevision/configuration_llava_onevision.py
index d9f35dc7dc28..cb957a992216 100644
--- a/src/transformers/models/llava_onevision/configuration_llava_onevision.py
+++ b/src/transformers/models/llava_onevision/configuration_llava_onevision.py
@@ -190,7 +190,7 @@ def __init__(
         super().__init__(**kwargs)
 
         # Due to a mismatch at model addition-time, the `tie_word_embeddings` was saved in the text config, even
-        # though it concerns the main model... So we hardcode a fix here
+        # though it concerns the main model, while it was set to False by default in the main model... So we hardcode a fix here
         if not self.tie_word_embeddings and self.text_config.tie_word_embeddings:
             self.tie_word_embeddings = True
             self.text_config.tie_word_embeddings = False

From 7c9f5ad8079e6f671ea438d7ab6cedfcfb0c1026 Mon Sep 17 00:00:00 2001
From: Cyril Vallez <cyril.vallez@gmail.com>
Date: Mon, 1 Dec 2025 17:25:53 +0100
Subject: [PATCH 22/25] revert

---
 src/transformers/core_model_loading.py        |  1 +
 src/transformers/integrations/hub_kernels.py  |  6 ---
 .../models/fsmt/configuration_fsmt.py         |  1 -
 .../modular_llava_next_video.py               |  9 +++-
 .../models/musicgen/configuration_musicgen.py |  6 ---
 .../configuration_musicgen_melody.py          |  7 ---
 tests/models/fsmt/test_modeling_fsmt.py       |  3 --
 tests/test_modeling_common.py                 | 43 -------------------
 8 files changed, 8 insertions(+), 68 deletions(-)

diff --git a/src/transformers/core_model_loading.py b/src/transformers/core_model_loading.py
index 81854dda1b74..b3cb6ebd1be4 100644
--- a/src/transformers/core_model_loading.py
+++ b/src/transformers/core_model_loading.py
@@ -594,6 +594,7 @@ def set_param_for_module(
             missing_keys.discard(target_name)
             if ref is not None and ref.shape != param_value.shape and hf_quantizer is None:
                 mismatch_keys.add((target_name, param_value.shape, ref.shape))
+                module_obj.param_name._is_hf_initialized = False  # Needs to be initialized
             else:
                 # super important otherwise _init_weight will re-init the param
                 param_value._is_hf_initialized = True
diff --git a/src/transformers/integrations/hub_kernels.py b/src/transformers/integrations/hub_kernels.py
index 7974fa4dd173..8d3ae310687e 100644
--- a/src/transformers/integrations/hub_kernels.py
+++ b/src/transformers/integrations/hub_kernels.py
@@ -341,12 +341,6 @@ def lazy_load_kernel(kernel_name: str, mapping: dict[str, ModuleType | None] = _
             mapping[kernel_name] = kernel
         except FileNotFoundError:
             mapping[kernel_name] = None
-        except AssertionError as error:
-            logger.warning_once(
-                f"Failed to load the '{kernel_name}' kernel from '{repo_id}' because the current environment does not "
-                f"support the required backend: {error}"
-            )
-            mapping[kernel_name] = None
 
     else:
         # Try to import is_{kernel_name}_available from ..utils
diff --git a/src/transformers/models/fsmt/configuration_fsmt.py b/src/transformers/models/fsmt/configuration_fsmt.py
index fc68464f252f..a1075016c3f4 100644
--- a/src/transformers/models/fsmt/configuration_fsmt.py
+++ b/src/transformers/models/fsmt/configuration_fsmt.py
@@ -194,7 +194,6 @@ def __init__(
             bos_token_id=eos_token_id,
             is_encoder_decoder=is_encoder_decoder,
             num_hidden_layers=encoder_layers,
-            tie_word_embeddings=tie_word_embeddings,
         )
         if "decoder" in common_kwargs:
             del common_kwargs["decoder"]
diff --git a/src/transformers/models/llava_next_video/modular_llava_next_video.py b/src/transformers/models/llava_next_video/modular_llava_next_video.py
index 4fec99df3b30..5cb0a6b9c4a0 100644
--- a/src/transformers/models/llava_next_video/modular_llava_next_video.py
+++ b/src/transformers/models/llava_next_video/modular_llava_next_video.py
@@ -121,7 +121,6 @@ def __init__(
         vision_feature_select_strategy="default",
         vision_feature_layer=-2,
         image_grid_pinpoints=None,
-        tie_word_embeddings=False,
         video_token_index=32000,
         spatial_pool_mode="average",
         spatial_pool_stride=2,
@@ -178,7 +177,13 @@ def __init__(
 
         self.text_config = text_config
 
-        super().__init__(tie_word_embeddings=tie_word_embeddings, **kwargs)
+        super().__init__(**kwargs)
+
+        # Due to a mismatch at model addition-time, the `tie_word_embeddings` was saved in the text config, even
+        # though it concerns the main model, while it was set to False by default in the main model... So we hardcode a fix here
+        if not self.tie_word_embeddings and self.text_config.tie_word_embeddings:
+            self.tie_word_embeddings = True
+            self.text_config.tie_word_embeddings = False
 
 
 class LlavaNextVideoModelOutputWithPast(LlavaNextModelOutputWithPast):
diff --git a/src/transformers/models/musicgen/configuration_musicgen.py b/src/transformers/models/musicgen/configuration_musicgen.py
index bff720e5cfe2..76c951668f46 100644
--- a/src/transformers/models/musicgen/configuration_musicgen.py
+++ b/src/transformers/models/musicgen/configuration_musicgen.py
@@ -221,11 +221,5 @@ def __init__(self, text_encoder, audio_encoder, decoder, **kwargs):
     def sampling_rate(self):
         return self.audio_encoder.sampling_rate
 
-    # overriding these because they crash - not 100% sure of that one
-    def get_text_config(self, decoder=None, encoder=None):
-        if decoder is None and encoder is None:
-            decoder = True
-        return super().get_text_config(decoder=decoder, encoder=encoder)
-
 
 __all__ = ["MusicgenConfig", "MusicgenDecoderConfig"]
diff --git a/src/transformers/models/musicgen_melody/configuration_musicgen_melody.py b/src/transformers/models/musicgen_melody/configuration_musicgen_melody.py
index af184b241408..cf1b9e4d8285 100644
--- a/src/transformers/models/musicgen_melody/configuration_musicgen_melody.py
+++ b/src/transformers/models/musicgen_melody/configuration_musicgen_melody.py
@@ -234,11 +234,4 @@ def __init__(
     def sampling_rate(self):
         return self.audio_encoder.sampling_rate
 
-    # overriding these because they crash - not 100% sure of that one
-    def get_text_config(self, decoder=None, encoder=None):
-        if decoder is None and encoder is None:
-            decoder = True
-        return super().get_text_config(decoder=decoder, encoder=encoder)
-
-
 __all__ = ["MusicgenMelodyConfig", "MusicgenMelodyDecoderConfig"]
diff --git a/tests/models/fsmt/test_modeling_fsmt.py b/tests/models/fsmt/test_modeling_fsmt.py
index d14c6b3225a2..acc29cac7ec0 100644
--- a/tests/models/fsmt/test_modeling_fsmt.py
+++ b/tests/models/fsmt/test_modeling_fsmt.py
@@ -125,7 +125,6 @@ def get_config(self):
             eos_token_id=self.eos_token_id,
             bos_token_id=self.bos_token_id,
             pad_token_id=self.pad_token_id,
-            tie_word_embeddings=True,
         )
 
     def prepare_config_and_inputs_for_common(self):
@@ -255,7 +254,6 @@ def test_ensure_weights_are_shared(self):
         config, inputs_dict = self.model_tester.prepare_config_and_inputs()
 
         config.tie_word_embeddings = True
-        config.decoder.tie_word_embeddings = True
         model = FSMTForConditionalGeneration(config)
 
         # FSMT shares three weights.
@@ -272,7 +270,6 @@ def test_ensure_weights_are_shared(self):
         )
 
         config.tie_word_embeddings = False
-        config.decoder.tie_word_embeddings = False
         model = FSMTForConditionalGeneration(config)
 
         # FSMT shares three weights.
diff --git a/tests/test_modeling_common.py b/tests/test_modeling_common.py
index 46f644e080bb..d2b5e0949cac 100755
--- a/tests/test_modeling_common.py
+++ b/tests/test_modeling_common.py
@@ -2103,49 +2103,6 @@ def test_tied_weights_keys(self):
                 f"Missing `_tied_weights_keys` for {model_class}: add all of {tied_params} except one.",
             )
 
-    def test_tie_word_embeddings_is_authoritative(self):
-        original_config, _ = self.model_tester.prepare_config_and_inputs_for_common()
-
-        for model_class in self.all_model_classes:
-            tied_config = copy.deepcopy(original_config)
-            tied_config.get_text_config().tie_word_embeddings = True
-
-            untied_config = copy.deepcopy(original_config)
-            untied_config.get_text_config().tie_word_embeddings = False
-
-            model_tied = model_class(tied_config)
-            model_untied = model_class(untied_config)
-
-            if not hasattr(model_tied, "_tied_weights_keys") or not model_tied._tied_weights_keys:
-                continue
-
-            tied_keys = model_tied._tied_weights_keys
-            state_dict_tied = model_tied.state_dict()
-            state_dict_untied = model_untied.state_dict()
-
-            for target_key, source_key in tied_keys.items():
-                if target_key not in state_dict_tied or source_key not in state_dict_tied:
-                    continue
-                if target_key not in state_dict_untied or source_key not in state_dict_untied:
-                    continue
-
-                target_tied_ptr = id_tensor_storage(state_dict_tied[target_key])
-                source_tied_ptr = id_tensor_storage(state_dict_tied[source_key])
-                target_untied_ptr = id_tensor_storage(state_dict_untied[target_key])
-                source_untied_ptr = id_tensor_storage(state_dict_untied[source_key])
-
-                self.assertEqual(
-                    target_tied_ptr,
-                    source_tied_ptr,
-                    f"{model_class}: With tie_word_embeddings=True, '{target_key}' should share storage with '{source_key}'",
-                )
-                self.assertNotEqual(
-                    target_untied_ptr,
-                    source_untied_ptr,
-                    f"{model_class}: With tie_word_embeddings=False, '{target_key}' should NOT share storage with '{source_key}'. "
-                    f"Config tie_word_embeddings must be authoritative over class-level _tied_weights_keys.",
-                )
-
     def test_model_weights_reload_no_missing_tied_weights(self):
         for model_class in self.all_model_classes:
             config, _ = self.model_tester.prepare_config_and_inputs_for_common()

From c4c457528c9dd97591cab1d8056ef9d23fc14b4a Mon Sep 17 00:00:00 2001
From: Cyril Vallez <cyril.vallez@gmail.com>
Date: Mon, 1 Dec 2025 17:27:24 +0100
Subject: [PATCH 23/25] fix

---
 .../models/musicgen_melody/configuration_musicgen_melody.py      | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/transformers/models/musicgen_melody/configuration_musicgen_melody.py b/src/transformers/models/musicgen_melody/configuration_musicgen_melody.py
index cf1b9e4d8285..a4ec8528590a 100644
--- a/src/transformers/models/musicgen_melody/configuration_musicgen_melody.py
+++ b/src/transformers/models/musicgen_melody/configuration_musicgen_melody.py
@@ -234,4 +234,5 @@ def __init__(
     def sampling_rate(self):
         return self.audio_encoder.sampling_rate
 
+
 __all__ = ["MusicgenMelodyConfig", "MusicgenMelodyDecoderConfig"]

From bbfea0c0c72fafb7f3c186c47fe9974443b7962a Mon Sep 17 00:00:00 2001
From: Cyril Vallez <cyril.vallez@gmail.com>
Date: Mon, 1 Dec 2025 17:30:49 +0100
Subject: [PATCH 24/25] modular

---
 .../modular_kyutai_speech_to_text.py          |  1 +
 .../configuration_llava_onevision.py          | 52 +++++++++----------
 2 files changed, 26 insertions(+), 27 deletions(-)

diff --git a/src/transformers/models/kyutai_speech_to_text/modular_kyutai_speech_to_text.py b/src/transformers/models/kyutai_speech_to_text/modular_kyutai_speech_to_text.py
index 790482c33727..31abf2408d12 100644
--- a/src/transformers/models/kyutai_speech_to_text/modular_kyutai_speech_to_text.py
+++ b/src/transformers/models/kyutai_speech_to_text/modular_kyutai_speech_to_text.py
@@ -251,6 +251,7 @@ def __init__(self, config):
 
 
 class KyutaiSpeechToTextForConditionalGeneration(LlamaForCausalLM, GenerationMixin):
+    _tied_weights_keys = {"lm_head.weight": "model.embed_tokens.embed_tokens.weight"}
     _keep_in_fp32_modules_strict = ["codec_model"]
     output_modalities = ("audio", "text")
 
diff --git a/src/transformers/models/llava_onevision/configuration_llava_onevision.py b/src/transformers/models/llava_onevision/configuration_llava_onevision.py
index cb957a992216..e76f77288c13 100644
--- a/src/transformers/models/llava_onevision/configuration_llava_onevision.py
+++ b/src/transformers/models/llava_onevision/configuration_llava_onevision.py
@@ -35,33 +35,31 @@ class LlavaOnevisionConfig(PreTrainedConfig):
     documentation from [`PreTrainedConfig`] for more information.
 
     Args:
-        vision_config (`Union[AutoConfig, dict]`,  *optional*, defaults to `SiglipVisionConfig`):
-            The config object or dictionary of the vision backbone.
-        text_config (`Union[AutoConfig, dict]`, *optional*, defaults to `Qwen2Config`):
-            The config object or dictionary of the text backbone.
-        image_token_index (`int`, *optional*, defaults to 151646):
-            The image token index to encode the image prompt.
-        video_token_index (`int`, *optional*, defaults to 151647):
-            The video token index to encode the video prompt.
-        projector_hidden_act (`str`, *optional*, defaults to `"gelu"`):
-            The activation function used by the multimodal projector.
-        vision_feature_select_strategy (`str`, *optional*, defaults to `"full"`):
-            The feature selection strategy used to select the vision feature from the vision backbone.
-            Can be one of `"default"` or `"full"`. If `"default"`, the CLS token is removed from the vision features.
-            If `"full"`, the full vision features are used.
-        vision_feature_layer (`Union[int, list[int]]`, *optional*, defaults to -1):
-            The index of the layer to select the vision feature. If multiple indices are provided,
-            the vision feature of the corresponding indices will be concatenated to form the
-            vision features.
-        vision_aspect_ratio (`str`, *optional*, defaults to `"anyres_max_9"`):
-            Aspect ratio used when processong image features. The default value is "anyres_max_9".
-        image_grid_pinpoints (`List`, *optional*):
-            A list of possible resolutions to use for processing high resolution images. Each item in the list should be a tuple or list
-            of the form `(height, width)`.
-        tie_word_embeddings (`bool`, *optional*, defaults to `False`):
-            Whether the model's input and output word embeddings should be tied.
-        multimodal_projector_bias (`bool`, *optional*, defaults to `True`):
-            Whether to use bias in the multimodal projector.
+            vision_config (`Union[AutoConfig, dict]`,  *optional*, defaults to `SiglipVisionConfig`):
+                The config object or dictionary of the vision backbone.
+            text_config (`Union[AutoConfig, dict]`, *optional*, defaults to `Qwen2Config`):
+                The config object or dictionary of the text backbone.
+            image_token_index (`int`, *optional*, defaults to 151646):
+                The image token index to encode the image prompt.
+            video_token_index (`int`, *optional*, defaults to 151647):
+                The video token index to encode the video prompt.
+            projector_hidden_act (`str`, *optional*, defaults to `"gelu"`):
+                The activation function used by the multimodal projector.
+            vision_feature_select_strategy (`str`, *optional*, defaults to `"full"`):
+                The feature selection strategy used to select the vision feature from the vision backbone.
+                Can be one of `"default"` or `"full"`. If `"default"`, the CLS token is removed from the vision features.
+                If `"full"`, the full vision features are used.
+            vision_feature_layer (`Union[int, list[int]]`, *optional*, defaults to -1):
+                The index of the layer to select the vision feature. If multiple indices are provided,
+                the vision feature of the corresponding indices will be concatenated to form the
+                vision features.
+            vision_aspect_ratio (`str`, *optional*, defaults to `"anyres_max_9"`):
+                Aspect ratio used when processong image features. The default value is "anyres_max_9".
+            image_grid_pinpoints (`List`, *optional*):
+                A list of possible resolutions to use for processing high resolution images. Each item in the list should be a tuple or list
+                of the form `(height, width)`.
+            multimodal_projector_bias (`bool`, *optional*, defaults to `True`):
+                Whether to use bias in the multimodal projector.
 
     Example:
 

From 9b157afeb23042d9798223c2cbc840c21e2e7af8 Mon Sep 17 00:00:00 2001
From: Cyril Vallez <cyril.vallez@gmail.com>
Date: Mon, 1 Dec 2025 17:34:58 +0100
Subject: [PATCH 25/25] modular

---
 .../configuration_llava_next_video.py         |  2 -
 .../modular_llava_next_video.py               |  2 -
 .../configuration_llava_onevision.py          | 50 +++++++++----------
 3 files changed, 25 insertions(+), 29 deletions(-)

diff --git a/src/transformers/models/llava_next_video/configuration_llava_next_video.py b/src/transformers/models/llava_next_video/configuration_llava_next_video.py
index 86dec22c8e5b..32ea6e7a14af 100644
--- a/src/transformers/models/llava_next_video/configuration_llava_next_video.py
+++ b/src/transformers/models/llava_next_video/configuration_llava_next_video.py
@@ -54,8 +54,6 @@ class LlavaNextVideoConfig(PreTrainedConfig):
         image_grid_pinpoints (`List`, *optional*, defaults to `[[336, 672], [672, 336], [672, 672], [1008, 336], [336, 1008]]`):
             A list of possible resolutions to use for processing high resolution images. Each item in the list should be a tuple or list
             of the form `(height, width)`.
-        tie_word_embeddings (`bool`, *optional*, defaults to `False`):
-            Whether the model's input and output word embeddings should be tied.
         video_token_index (`int`, *optional*, defaults to 32000):
             The video token index to encode the image prompt.
         spatial_pool_mode (`str`, *optional*, defaults to `"average"`):
diff --git a/src/transformers/models/llava_next_video/modular_llava_next_video.py b/src/transformers/models/llava_next_video/modular_llava_next_video.py
index 5cb0a6b9c4a0..61b4b5fdf920 100644
--- a/src/transformers/models/llava_next_video/modular_llava_next_video.py
+++ b/src/transformers/models/llava_next_video/modular_llava_next_video.py
@@ -72,8 +72,6 @@ class LlavaNextVideoConfig(PreTrainedConfig):
         image_grid_pinpoints (`List`, *optional*, defaults to `[[336, 672], [672, 336], [672, 672], [1008, 336], [336, 1008]]`):
             A list of possible resolutions to use for processing high resolution images. Each item in the list should be a tuple or list
             of the form `(height, width)`.
-        tie_word_embeddings (`bool`, *optional*, defaults to `False`):
-            Whether the model's input and output word embeddings should be tied.
         video_token_index (`int`, *optional*, defaults to 32000):
             The video token index to encode the image prompt.
         spatial_pool_mode (`str`, *optional*, defaults to `"average"`):
diff --git a/src/transformers/models/llava_onevision/configuration_llava_onevision.py b/src/transformers/models/llava_onevision/configuration_llava_onevision.py
index e76f77288c13..b72c2235ed7e 100644
--- a/src/transformers/models/llava_onevision/configuration_llava_onevision.py
+++ b/src/transformers/models/llava_onevision/configuration_llava_onevision.py
@@ -35,31 +35,31 @@ class LlavaOnevisionConfig(PreTrainedConfig):
     documentation from [`PreTrainedConfig`] for more information.
 
     Args:
-            vision_config (`Union[AutoConfig, dict]`,  *optional*, defaults to `SiglipVisionConfig`):
-                The config object or dictionary of the vision backbone.
-            text_config (`Union[AutoConfig, dict]`, *optional*, defaults to `Qwen2Config`):
-                The config object or dictionary of the text backbone.
-            image_token_index (`int`, *optional*, defaults to 151646):
-                The image token index to encode the image prompt.
-            video_token_index (`int`, *optional*, defaults to 151647):
-                The video token index to encode the video prompt.
-            projector_hidden_act (`str`, *optional*, defaults to `"gelu"`):
-                The activation function used by the multimodal projector.
-            vision_feature_select_strategy (`str`, *optional*, defaults to `"full"`):
-                The feature selection strategy used to select the vision feature from the vision backbone.
-                Can be one of `"default"` or `"full"`. If `"default"`, the CLS token is removed from the vision features.
-                If `"full"`, the full vision features are used.
-            vision_feature_layer (`Union[int, list[int]]`, *optional*, defaults to -1):
-                The index of the layer to select the vision feature. If multiple indices are provided,
-                the vision feature of the corresponding indices will be concatenated to form the
-                vision features.
-            vision_aspect_ratio (`str`, *optional*, defaults to `"anyres_max_9"`):
-                Aspect ratio used when processong image features. The default value is "anyres_max_9".
-            image_grid_pinpoints (`List`, *optional*):
-                A list of possible resolutions to use for processing high resolution images. Each item in the list should be a tuple or list
-                of the form `(height, width)`.
-            multimodal_projector_bias (`bool`, *optional*, defaults to `True`):
-                Whether to use bias in the multimodal projector.
+        vision_config (`Union[AutoConfig, dict]`,  *optional*, defaults to `SiglipVisionConfig`):
+            The config object or dictionary of the vision backbone.
+        text_config (`Union[AutoConfig, dict]`, *optional*, defaults to `Qwen2Config`):
+            The config object or dictionary of the text backbone.
+        image_token_index (`int`, *optional*, defaults to 151646):
+            The image token index to encode the image prompt.
+        video_token_index (`int`, *optional*, defaults to 151647):
+            The video token index to encode the video prompt.
+        projector_hidden_act (`str`, *optional*, defaults to `"gelu"`):
+            The activation function used by the multimodal projector.
+        vision_feature_select_strategy (`str`, *optional*, defaults to `"full"`):
+            The feature selection strategy used to select the vision feature from the vision backbone.
+            Can be one of `"default"` or `"full"`. If `"default"`, the CLS token is removed from the vision features.
+            If `"full"`, the full vision features are used.
+        vision_feature_layer (`Union[int, list[int]]`, *optional*, defaults to -1):
+            The index of the layer to select the vision feature. If multiple indices are provided,
+            the vision feature of the corresponding indices will be concatenated to form the
+            vision features.
+        vision_aspect_ratio (`str`, *optional*, defaults to `"anyres_max_9"`):
+            Aspect ratio used when processong image features. The default value is "anyres_max_9".
+        image_grid_pinpoints (`List`, *optional*):
+            A list of possible resolutions to use for processing high resolution images. Each item in the list should be a tuple or list
+            of the form `(height, width)`.
+        multimodal_projector_bias (`bool`, *optional*, defaults to `True`):
+            Whether to use bias in the multimodal projector.
 
     Example: