diff --git a/flashinfer-aot/setup.py b/flashinfer-aot/setup.py
index 5c541026..80fd4ea9 100644
--- a/flashinfer-aot/setup.py
+++ b/flashinfer-aot/setup.py
@@ -16,6 +16,7 @@
 
 from typing import List, Tuple
 
+import copy
 import pathlib
 import os
 import re
@@ -372,7 +373,7 @@ def __init__(self, *args, **kwargs) -> None:
             "-use_fast_math",
         ],
     }
-    extra_compile_args_sm90 = extra_compile_args.copy()
+    extra_compile_args_sm90 = copy.deepcopy(extra_compile_args)
     extra_compile_args_sm90["nvcc"].extend(
         "-gencode arch=compute_90a,code=sm_90a".split()
     )