diff --git a/iris-mpc-gpu/tests/extract_msb_mod.rs b/iris-mpc-gpu/tests/extract_msb_mod.rs
index 35499fce1..52c0b4838 100644
--- a/iris-mpc-gpu/tests/extract_msb_mod.rs
+++ b/iris-mpc-gpu/tests/extract_msb_mod.rs
@@ -109,7 +109,7 @@ mod extract_msb_mod_test {
         let mod_ = 1u64 << (16 + B_BITS);
         let mut res = Vec::with_capacity(input.len());
         for inp in input {
-            let r = (u64::MAX - ((inp as u64) << B_BITS) + 1) % mod_;
+            let r = (u64::MAX - ((inp as u64) << B_BITS) + 2) % mod_;
             let msb = r >> (B_BITS + 16 - 1) & 1 == 1;
             res.push(msb)
         }