diff --git a/tests/python/test_ad_math_func.py b/tests/python/test_ad_math_func.py
index 2d66450593dd8f..34192d5d9beb99 100644
--- a/tests/python/test_ad_math_func.py
+++ b/tests/python/test_ad_math_func.py
@@ -2,7 +2,7 @@
 from tests import test_utils
 
 
-@test_utils.test(require=ti.extension.adstack)
+@test_utils.test(require=ti.extension.adstack, dynamic_index=False)
 def test_polar_decompose_2D():
     # `polar_decompose3d` in current Taichi version (v1.1) does not support autodiff,
     # becasue it mixed usage of for-loops and statements without looping.