diff --git a/invokeai/app/invocations/baseinvocation.py b/invokeai/app/invocations/baseinvocation.py
index f86dc2d9a1..78d85b4d33 100644
--- a/invokeai/app/invocations/baseinvocation.py
+++ b/invokeai/app/invocations/baseinvocation.py
@@ -192,12 +192,19 @@ class BaseInvocation(ABC, BaseModel):
         """Gets a pydantc TypeAdapter for the union of all invocation types."""
         if not cls._typeadapter or cls._typeadapter_needs_update:
             AnyInvocation = TypeAliasType(
-                "AnyInvocation", Annotated[Union[tuple(cls._invocation_classes)], Field(discriminator="type")]
+                "AnyInvocation", Annotated[Union[tuple(cls.get_invocations())], Field(discriminator="type")]
             )
             cls._typeadapter = TypeAdapter(AnyInvocation)
             cls._typeadapter_needs_update = False
         return cls._typeadapter
 
+    @classmethod
+    def invalidate_typeadapter(cls) -> None:
+        """Invalidates the typeadapter, forcing it to be rebuilt on next access. If the invocation allowlist or
+        denylist is changed, this should be called to ensure the typeadapter is updated and validation respects
+        the updated allowlist and denylist."""
+        cls._typeadapter_needs_update = True
+
     @classmethod
     def get_invocations(cls) -> Iterable[BaseInvocation]:
         """Gets all invocations, respecting the allowlist and denylist."""
diff --git a/tests/test_config.py b/tests/test_config.py
index a6ea2a3480..c7149edc73 100644
--- a/tests/test_config.py
+++ b/tests/test_config.py
@@ -3,15 +3,16 @@ from tempfile import TemporaryDirectory
 from typing import Any
 
 import pytest
-from omegaconf import OmegaConf
 from pydantic import ValidationError
 
+from invokeai.app.invocations.baseinvocation import BaseInvocation
 from invokeai.app.services.config.config_default import (
     DefaultInvokeAIAppConfig,
     InvokeAIAppConfig,
     get_config,
     load_and_migrate_config,
 )
+from invokeai.app.services.shared.graph import Graph
 from invokeai.frontend.cli.arg_parser import InvokeAIArgs
 
 v4_config = """
@@ -265,57 +266,29 @@ def test_get_config_writing(patch_rootdir: None, monkeypatch: pytest.MonkeyPatch
     InvokeAIArgs.did_parse = False
 
 
-@pytest.mark.xfail(
-    reason="""
-    This test fails when run as part of the full test suite.
-
-    This test needs to deny nodes from being included in the InvocationsUnion by providing
-    an app configuration as a test fixture. Pytest executes all test files before running
-    tests, so the app configuration is already initialized by the time this test runs, and
-    the InvocationUnion is already created and the denied nodes are not omitted from it.
-
-    This test passes when `test_config.py` is tested in isolation.
-
-    Perhaps a solution would be to call `get_app_config().parse_args()` in
-    other test files?
-    """
-)
 def test_deny_nodes(patch_rootdir):
     # Allow integer, string and float, but explicitly deny float
-    allow_deny_nodes_conf = OmegaConf.create(
-        """
-        InvokeAI:
-          Nodes:
-            allow_nodes:
-              - integer
-              - string
-              - float
-            deny_nodes:
-              - float
-        """
-    )
-    # must parse config before importing Graph, so its nodes union uses the config
-    get_config.cache_clear()
     conf = get_config()
-    get_config.cache_clear()
-    conf.merge_from_file(conf=allow_deny_nodes_conf, argv=[])
-    from invokeai.app.services.shared.graph import Graph
+    conf.allow_nodes = ["integer", "string", "float"]
+    conf.deny_nodes = ["float"]
+
+    # We've changed the config, we need to invalidate the typeadapter cache so that the new config is used for
+    # subsequent graph validations
+    BaseInvocation.invalidate_typeadapter()
 
     # confirm graph validation fails when using denied node
-    Graph(nodes={"1": {"id": "1", "type": "integer"}})
-    Graph(nodes={"1": {"id": "1", "type": "string"}})
+    Graph.model_validate({"nodes": {"1": {"id": "1", "type": "integer"}}})
+    Graph.model_validate({"nodes": {"1": {"id": "1", "type": "string"}}})
 
     with pytest.raises(ValidationError):
-        Graph(nodes={"1": {"id": "1", "type": "float"}})
-
-    from invokeai.app.invocations.baseinvocation import BaseInvocation
+        Graph.model_validate({"nodes": {"1": {"id": "1", "type": "float"}}})
 
     # confirm invocations union will not have denied nodes
     all_invocations = BaseInvocation.get_invocations()
 
-    has_integer = len([i for i in all_invocations if i.model_fields.get("type").default == "integer"]) == 1
-    has_string = len([i for i in all_invocations if i.model_fields.get("type").default == "string"]) == 1
-    has_float = len([i for i in all_invocations if i.model_fields.get("type").default == "float"]) == 1
+    has_integer = len([i for i in all_invocations if i.get_type() == "integer"]) == 1
+    has_string = len([i for i in all_invocations if i.get_type() == "string"]) == 1
+    has_float = len([i for i in all_invocations if i.get_type() == "float"]) == 1
 
     assert has_integer
     assert has_string