diff --git a/docs/conf.py b/docs/conf.py
index f5e7bca76..683a6c0a9 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -9,8 +9,8 @@
 project = 'pyk'
 author = 'Runtime Verification, Inc'
 copyright = '2024, Runtime Verification, Inc'
-version = '0.1.622'
-release = '0.1.622'
+version = '0.1.623'
+release = '0.1.623'
 
 # -- General configuration ---------------------------------------------------
 # https://www.sphinx-doc.org/en/master/usage/configuration.html#general-configuration
diff --git a/package/version b/package/version
index a502218f6..cc5737c83 100644
--- a/package/version
+++ b/package/version
@@ -1 +1 @@
-0.1.622
+0.1.623
diff --git a/pyproject.toml b/pyproject.toml
index 0bde8c37b..c701d7d49 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "poetry.core.masonry.api"
 
 [tool.poetry]
 name = "pyk"
-version = "0.1.622"
+version = "0.1.623"
 description = ""
 authors = [
     "Runtime Verification, Inc. <contact@runtimeverification.com>",
diff --git a/src/pyk/proof/reachability.py b/src/pyk/proof/reachability.py
index 818ca5af3..e4812847a 100644
--- a/src/pyk/proof/reachability.py
+++ b/src/pyk/proof/reachability.py
@@ -198,7 +198,9 @@ def from_dict(cls: type[APRProof], dct: Mapping[str, Any], proof_dir: Path | Non
         subproof_ids = dct['subproof_ids'] if 'subproof_ids' in dct else []
         node_refutations: dict[int, str] = {}
         if 'node_refutation' in dct:
-            node_refutations = {kcfg._resolve(node_id): proof_id for (node_id, proof_id) in dct['node_refutations']}
+            node_refutations = {
+                kcfg._resolve(int(node_id)): proof_id for node_id, proof_id in dct['node_refutations'].items()
+            }
         if 'logs' in dct:
             logs = {int(k): tuple(LogEntry.from_dict(l) for l in ls) for k, ls in dct['logs'].items()}
         else:
@@ -404,7 +406,9 @@ def read_proof_data(proof_dir: Path, id: str) -> APRProof:
         terminal = proof_dict['terminal']
         logs = {int(k): tuple(LogEntry.from_dict(l) for l in ls) for k, ls in proof_dict['logs'].items()}
         subproof_ids = proof_dict['subproof_ids']
-        node_refutations = {kcfg._resolve(node_id): proof_id for (node_id, proof_id) in proof_dict['node_refutations']}
+        node_refutations = {
+            kcfg._resolve(int(node_id)): proof_id for node_id, proof_id in proof_dict['node_refutations'].items()
+        }
 
         return APRProof(
             id=id,
@@ -474,6 +478,10 @@ def unrefute_node(self, node: KCFG.Node) -> None:
         _LOGGER.info(f'Disabled refutation of node {node.id}.')
 
     def construct_node_refutation(self, node: KCFG.Node) -> RefutationProof | None:  # TODO put into prover class
+        if len(self.kcfg.successors(node.id)) > 0:
+            _LOGGER.error(f'Cannot refute node {node.id} that already has successors')
+            return None
+
         path = single(self.kcfg.paths_between(source_id=self.init, target_id=node.id))
         branches_on_path = list(filter(lambda x: type(x) is KCFG.Split or type(x) is KCFG.NDBranch, reversed(path)))
         if len(branches_on_path) == 0:
diff --git a/src/pyk/proof/show.py b/src/pyk/proof/show.py
index 5564e8d6e..31a990939 100644
--- a/src/pyk/proof/show.py
+++ b/src/pyk/proof/show.py
@@ -36,6 +36,8 @@ def node_attrs(self, kcfg: KCFG, node: KCFG.Node) -> list[str]:
             attrs.append('target')
         if self.proof.is_pending(node.id):
             attrs.append('pending')
+        if self.proof.is_refuted(node.id):
+            attrs.append('refuted')
         if self.proof.is_terminal(node.id):
             attrs.append('terminal')
             if 'stuck' in attrs: