diff --git a/src/gadgets/is_zero.rs b/src/gadgets/is_zero.rs
index 4aef2953..a4d9a210 100644
--- a/src/gadgets/is_zero.rs
+++ b/src/gadgets/is_zero.rs
@@ -55,6 +55,10 @@ impl IsZeroGadget {
             "value is 0 or inverse_or_zero is inverse of value",
             value.current() * (Query::one() - value.current() * inverse_or_zero.current()),
         );
+        cb.assert_zero(
+            "inverse_or_zero is 0 or inverse_or_zero is inverse of value",
+            inverse_or_zero.current() * (Query::one() - value.current() * inverse_or_zero.current()),
+        );
         Self {
             value,
             inverse_or_zero,