diff --git a/src/libcore/num/mod.rs b/src/libcore/num/mod.rs
index 15ffe9db8ce6..bef7a20cd7f3 100644
--- a/src/libcore/num/mod.rs
+++ b/src/libcore/num/mod.rs
@@ -2348,7 +2348,7 @@ macro_rules! uint_impl {
             if self == 0 {
                 1
             } else {
-                one << (bits - self.wrapping_sub(one).leading_zeros() as usize)
+                one << (bits - (self - one).leading_zeros() as usize)
             }
         }