diff --git a/tests/test_generate_popular_node_signatures.py b/tests/test_generate_popular_node_signatures.py
index ce59b12..a5461ce 100644
--- a/tests/test_generate_popular_node_signatures.py
+++ b/tests/test_generate_popular_node_signatures.py
@@ -1359,6 +1359,36 @@ NODE_CLASS_MAPPINGS = {
         self.assertEqual({}, result["nodes"])
         self.assertEqual("no_static_nodes", result["pack"]["status"])
 
+    def test_class_body_plain_function_decorator_invalidates_static_input_env(self):
+        source = '''
+INPUTS = {
+    "required": {
+        "image": ("IMAGE",),
+    },
+}
+
+
+class ClassPlainDecoratorInputEnvNode:
+    RETURN_TYPES = ("IMAGE",)
+
+    @decorator
+    def helper(self):
+        pass
+
+    @classmethod
+    def INPUT_TYPES(cls):
+        return INPUTS
+
+
+NODE_CLASS_MAPPINGS = {
+    "ClassPlainDecoratorInputEnvNode": ClassPlainDecoratorInputEnvNode,
+}
+'''
+        result = self._extract_source(source, "class-plain-decorator-input-env-pack")
+
+        self.assertEqual({}, result["nodes"])
+        self.assertEqual("no_static_nodes", result["pack"]["status"])
+
     def test_class_body_function_body_mutation_does_not_invalidate_static_input_env(self):
         source = '''
 INPUTS = {
@@ -4120,6 +4150,33 @@ def helper(x=DefinitionTimeMutatedMappedNode.RETURN_TYPES.clear()):
         self.assertEqual({}, result["nodes"])
         self.assertEqual("no_static_nodes", result["pack"]["status"])
 
+    def test_plain_decorated_function_after_mapping_skips_node(self):
+        source = '''
+class PlainDecoratedAfterMappingNode:
+    RETURN_TYPES = ["IMAGE"]
+
+    @classmethod
+    def INPUT_TYPES(cls):
+        return {
+            "required": {
+                "image": ("IMAGE",),
+            },
+        }
+
+
+NODE_CLASS_MAPPINGS = {
+    "PlainDecoratedAfterMappingNode": PlainDecoratedAfterMappingNode,
+}
+
+@decorator
+def helper():
+    pass
+'''
+        result = self._extract_source(source, "plain-decorated-after-mapping-pack")
+
+        self.assertEqual({}, result["nodes"])
+        self.assertEqual("no_static_nodes", result["pack"]["status"])
+
     def test_unhashable_node_mapping_key_skips_repo_without_raising(self):
         source = '''
 KEY = ["UnhashableMappingKeyNode"]
diff --git a/tools/generate_popular_node_signatures.py b/tools/generate_popular_node_signatures.py
index b4a7451..b713798 100644
--- a/tools/generate_popular_node_signatures.py
+++ b/tools/generate_popular_node_signatures.py
@@ -668,7 +668,13 @@ def _has_arbitrary_call(stmt):
 
     class ArbitraryCallPresenceVisitor(ast.NodeVisitor):
         def _visit_function_definition_expressions(self, node):
+            nonlocal found
             for decorator in node.decorator_list:
+                if not (
+                    isinstance(decorator, ast.Name)
+                    and decorator.id == "classmethod"
+                ):
+                    found = True
                 self.visit(decorator)
             self.visit(node.args)
             if node.returns is not None: