diff --git a/python/jittor/__init__.py b/python/jittor/__init__.py
index a1bdc29f..40cbdba9 100644
--- a/python/jittor/__init__.py
+++ b/python/jittor/__init__.py
@@ -186,7 +186,7 @@ def norm(x, k, dim):
     if k==1:
         return x.abs().sum(dim)
     if k==2:
-        return (x**2).sum(dim).sqrt()
+        return x.sqr().sum(dim).sqrt()
 Var.norm = norm
 
 origin_reshape = reshape