diff --git a/tools/onnx-graphsurgeon/onnx_graphsurgeon/ir/graph.py b/tools/onnx-graphsurgeon/onnx_graphsurgeon/ir/graph.py
index b40968f4..06acd19f 100644
--- a/tools/onnx-graphsurgeon/onnx_graphsurgeon/ir/graph.py
+++ b/tools/onnx-graphsurgeon/onnx_graphsurgeon/ir/graph.py
@@ -595,6 +595,7 @@ def get_used_funcs(nodes):
                 return inputs
 
             if get_id(node_or_func) in hierarchy_levels:
+                visited.remove(get_id(node_or_func))
                 return hierarchy_levels[get_id(node_or_func)].level
 
             # The level of a node is the level of its highest input + 1.