diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 0490ae968c2..363a414cf2a 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -58,6 +58,7 @@ repos:
           - py>=1.8.2
           - attrs>=19.2.0
           - packaging
+          - types-atomicwrites
           - types-toml
           - types-pkg_resources
 -   repo: local
diff --git a/changelog/7363.breaking.rst b/changelog/7363.breaking.rst
new file mode 100644
index 00000000000..76f881a04d7
--- /dev/null
+++ b/changelog/7363.breaking.rst
@@ -0,0 +1,23 @@
+**PytestDeprecationWarning are now errors by default.**
+
+Following our plan to remove deprecated features with as little disruption as
+possible, all warnings of type ``PytestDeprecationWarning`` now generate errors
+instead of warning messages.
+
+**The affected features will be effectively removed in pytest 7.1**, so please consult the
+`Deprecations and Removals <https://docs.pytest.org/en/stable/deprecations.html>`__
+section in the docs for directions on how to update existing code.
+
+In the pytest ``7.0.X`` series, it is possible to change the errors back into warnings as a
+stopgap measure by adding this to your ``pytest.ini`` file:
+
+.. code-block:: ini
+
+    [pytest]
+    filterwarnings =
+        ignore::pytest.PytestDeprecationWarning
+
+But this will stop working when pytest ``7.1`` is released.
+
+**If you have concerns** about the removal of a specific feature, please add a
+comment to `#7363 <https://github.com/pytest-dev/pytest/issues/7363>`__.
diff --git a/doc/en/example/assertion/global_testmodule_config/conftest.py b/doc/en/example/assertion/global_testmodule_config/conftest.py
index 7cdf18cdbc1..74a19bf6ac5 100644
--- a/doc/en/example/assertion/global_testmodule_config/conftest.py
+++ b/doc/en/example/assertion/global_testmodule_config/conftest.py
@@ -7,7 +7,9 @@
 
 def pytest_runtest_setup(item):
     if isinstance(item, pytest.Function):
-        if not item.fspath.relto(mydir):
+        try:
+            item.path.relative_to(mydir)
+        except ValueError:
             return
         mod = item.getparent(pytest.Module).obj
         if hasattr(mod, "hello"):
diff --git a/src/_pytest/warnings.py b/src/_pytest/warnings.py
index 35eed96df58..f99199e0a72 100644
--- a/src/_pytest/warnings.py
+++ b/src/_pytest/warnings.py
@@ -49,6 +49,8 @@ def catch_warnings_for_item(
             warnings.filterwarnings("always", category=DeprecationWarning)
             warnings.filterwarnings("always", category=PendingDeprecationWarning)
 
+        warnings.filterwarnings("error", category=pytest.PytestDeprecationWarning)
+
         apply_warning_filters(config_filters, cmdline_filters)
 
         # apply filters from "filterwarnings" marks
diff --git a/testing/test_mark.py b/testing/test_mark.py
index 77991f9e273..d5c94379183 100644
--- a/testing/test_mark.py
+++ b/testing/test_mark.py
@@ -832,7 +832,9 @@ def test_two(): assert 1
             def test_three(): assert 1
         """
         )
-        reprec = pytester.inline_run("-k", "test_two:", threepass)
+        reprec = pytester.inline_run(
+            "-k", "test_two:", threepass, "-Wignore::pytest.PytestDeprecationWarning"
+        )
         passed, skipped, failed = reprec.listoutcomes()
         assert len(passed) == 2
         assert not failed
diff --git a/testing/test_nose.py b/testing/test_nose.py
index 77f79b53b3c..7de1959271f 100644
--- a/testing/test_nose.py
+++ b/testing/test_nose.py
@@ -334,7 +334,7 @@ def test_failing():
             assert False
         """
     )
-    result = pytester.runpytest(p)
+    result = pytester.runpytest(p, "-Wignore::pytest.PytestDeprecationWarning")
     result.assert_outcomes(skipped=1)
 
 
diff --git a/testing/test_terminal.py b/testing/test_terminal.py
index 3e3502b5ca9..58fd604d68b 100644
--- a/testing/test_terminal.py
+++ b/testing/test_terminal.py
@@ -683,7 +683,9 @@ def test_three():
                     pass
            """
         )
-        result = pytester.runpytest("-k", "test_two:", testpath)
+        result = pytester.runpytest(
+            "-k", "test_two:", testpath, "-Wignore::pytest.PytestDeprecationWarning"
+        )
         result.stdout.fnmatch_lines(
             ["collected 3 items / 1 deselected / 2 selected", "*test_deselected.py ..*"]
         )
diff --git a/testing/test_warnings.py b/testing/test_warnings.py
index 11678383548..9d1e9ef4de4 100644
--- a/testing/test_warnings.py
+++ b/testing/test_warnings.py
@@ -518,9 +518,6 @@ def test_hidden_by_system(self, pytester: Pytester, monkeypatch) -> None:
 
 
 @pytest.mark.parametrize("change_default", [None, "ini", "cmdline"])
-@pytest.mark.skip(
-    reason="This test should be enabled again before pytest 7.0 is released"
-)
 def test_deprecation_warning_as_error(pytester: Pytester, change_default) -> None:
     """This ensures that PytestDeprecationWarnings raised by pytest are turned into errors.