diff --git a/py/torch_tensorrt/dynamo/lowering/passes/constant_folding.py b/py/torch_tensorrt/dynamo/lowering/passes/constant_folding.py
index 0feec63316..10fddec5c0 100644
--- a/py/torch_tensorrt/dynamo/lowering/passes/constant_folding.py
+++ b/py/torch_tensorrt/dynamo/lowering/passes/constant_folding.py
@@ -1,3 +1,4 @@
+import importlib
 import logging
 from typing import Any
 
@@ -101,6 +102,7 @@ def __init__(self, *args: Any, **kwargs: Any) -> None:
 
     # TODO: Update this function when quantization is added
     def is_impure(self, node: torch.fx.node.Node) -> bool:
-        if node.target in (torch.ops.tensorrt.quantize_op.default,):
-            return True
+        if importlib.util.find_spec("modelopt"):
+            if node.target in (torch.ops.tensorrt.quantize_op.default,):
+                return True
         return False