diff --git a/src/librustc_data_structures/sip128.rs b/src/librustc_data_structures/sip128.rs
index 7838a9008902..e5de359e4759 100644
--- a/src/librustc_data_structures/sip128.rs
+++ b/src/librustc_data_structures/sip128.rs
@@ -237,7 +237,7 @@ impl Hasher for SipHasher128 {
 
         if self.ntail != 0 {
             needed = 8 - self.ntail;
-            self.tail |= unsafe { u8to64_le(msg, 0, cmp::min(length, needed)) } << 8 * self.ntail;
+            self.tail |= unsafe { u8to64_le(msg, 0, cmp::min(length, needed)) } << (8 * self.ntail);
             if length < needed {
                 self.ntail += length;
                 return