diff --git a/pandas/_testing.py b/pandas/_testing.py
index ef6232fa6d575..97047e0632087 100644
--- a/pandas/_testing.py
+++ b/pandas/_testing.py
@@ -787,7 +787,11 @@ def _get_ilevel_values(index, level):
     # skip exact index checking when `check_categorical` is False
     if check_exact and check_categorical:
         if not left.equals(right):
-            diff = np.sum((left.values != right.values).astype(int)) * 100.0 / len(left)
+            diff = (
+                np.sum((np.not_equal(left.values, right.values)).astype(int))
+                * 100.0
+                / len(left)
+            )
             msg = f"{obj} values are different ({np.round(diff, 5)} %)"
             raise_assert_detail(obj, msg, left, right)
     else: