diff --git a/comfy_execution/caching.py b/comfy_execution/caching.py
index 6c99274a5..dc785d21f 100644
--- a/comfy_execution/caching.py
+++ b/comfy_execution/caching.py
@@ -332,10 +332,10 @@ def to_hashable(obj, max_nodes=_MAX_SIGNATURE_CONTAINER_VISITS):
                     if items is None:
                         items = list(current.items())
                     ordered_items = [
-                        (_sanitized_sort_key(k, memo=sort_memo), resolve_value(k), resolve_value(v))
+                        (_sanitized_sort_key(k, memo=sort_memo), k, resolve_value(v))
                         for k, v in items
                     ]
-                    if any(is_failed(key) or is_failed(value) for _, key, value in ordered_items):
+                    if any(type(key) not in _PRIMITIVE_SIGNATURE_TYPES or is_failed(value) for _, key, value in ordered_items):
                         memo[current_id] = Unhashable()
                         continue
                     ordered_items.sort(key=lambda item: item[0])
@@ -398,9 +398,17 @@ def to_hashable(obj, max_nodes=_MAX_SIGNATURE_CONTAINER_VISITS):
                 memo[current_id] = Unhashable()
                 active.discard(current_id)
                 continue
-            for key, value in reversed(items):
-                work_stack.append((value, False))
-                work_stack.append((key, False))
+            for key, value in items:
+                if type(key) not in _PRIMITIVE_SIGNATURE_TYPES:
+                    snapshots.pop(current_id, None)
+                    memo[current_id] = Unhashable()
+                    active.discard(current_id)
+                    break
+            else:
+                for _, value in reversed(items):
+                    work_stack.append((value, False))
+                continue
+            continue
         else:
             try:
                 items = list(current)
diff --git a/tests-unit/execution_test/caching_test.py b/tests-unit/execution_test/caching_test.py
index 6effca064..2c63f68c8 100644
--- a/tests-unit/execution_test/caching_test.py
+++ b/tests-unit/execution_test/caching_test.py
@@ -225,6 +225,15 @@ def test_to_hashable_canonicalizes_dict_insertion_order(caching_module):
     assert caching.to_hashable(first) == caching.to_hashable(second)
 
 
+def test_to_hashable_fails_closed_for_opaque_dict_key(caching_module):
+    """Opaque dict keys should fail closed instead of being traversed during hashing."""
+    caching, _ = caching_module
+
+    hashable = caching.to_hashable({_OpaqueValue(): 1})
+
+    assert isinstance(hashable, caching.Unhashable)
+
+
 @pytest.mark.parametrize(
     "container_factory",
     [