diff --git a/comfy_execution/caching.py b/comfy_execution/caching.py
index fecf54d1e..1a5615627 100644
--- a/comfy_execution/caching.py
+++ b/comfy_execution/caching.py
@@ -68,15 +68,17 @@ _FAILED_SIGNATURE = object()
 
 
 def _shallow_is_changed_signature(value):
-    """Sanitize execution-time `is_changed` values with a small fail-closed budget."""
+    """Reduce execution-time `is_changed` values through a fail-closed builtin canonicalizer."""
     value_type = type(value)
     if value_type in _PRIMITIVE_SIGNATURE_TYPES:
         return value
 
-    canonical = to_hashable(value, max_nodes=64)
+    if value_type not in _CONTAINER_SIGNATURE_TYPES:
+        return Unhashable()
+
+    canonical = _signature_to_hashable(value, max_nodes=64)
     if type(canonical) is Unhashable:
         return canonical
-
     if value_type is list or value_type is tuple:
         container_tag = "is_changed_list" if value_type is list else "is_changed_tuple"
         return (container_tag, canonical[1])
diff --git a/tests/execution/test_caching.py b/tests/execution/test_caching.py
index 569bf5bd8..765ab0b91 100644
--- a/tests/execution/test_caching.py
+++ b/tests/execution/test_caching.py
@@ -25,6 +25,50 @@ class _StubNode:
         return {"required": {}}
 
 
+def test_shallow_is_changed_signature_keeps_primitive_only_list_shallow():
+    assert caching._shallow_is_changed_signature([1, "two", None, True]) == (
+        "is_changed_list",
+        (1, "two", None, True),
+    )
+
+
+def test_shallow_is_changed_signature_keeps_primitive_only_tuple_shallow():
+    assert caching._shallow_is_changed_signature((1, "two", None, True)) == (
+        "is_changed_tuple",
+        (1, "two", None, True),
+    )
+
+
+def test_shallow_is_changed_signature_keeps_structured_builtin_fingerprint_list():
+    assert caching._shallow_is_changed_signature([("seed", 42), {"cfg": 8}]) == (
+        "is_changed_list",
+        (
+            ("tuple", ("seed", 42)),
+            ("dict", (("cfg", 8),)),
+        ),
+    )
+
+
+def test_shallow_is_changed_signature_does_not_use_to_hashable(monkeypatch):
+    monkeypatch.setattr(
+        caching,
+        "to_hashable",
+        lambda *_args, **_kwargs: (_ for _ in ()).throw(
+            AssertionError("is_changed signature must not deep-canonicalize")
+        ),
+    )
+
+    signature = caching._shallow_is_changed_signature([("seed", 42), {"cfg": 8}])
+
+    assert signature == (
+        "is_changed_list",
+        (
+            ("tuple", ("seed", 42)),
+            ("dict", (("cfg", 8),)),
+        ),
+    )
+
+
 def test_get_immediate_node_signature_canonicalizes_non_link_inputs(monkeypatch):
     live_value = [1, {"nested": [2, 3]}]
     dynprompt = _StubDynPrompt(