diff --git a/lib/isc/include/isc/fxhash.h b/lib/isc/include/isc/fxhash.h
index 8cfbd32377..56273f55cb 100644
--- a/lib/isc/include/isc/fxhash.h
+++ b/lib/isc/include/isc/fxhash.h
@@ -40,7 +40,7 @@
 
 static inline size_t
 fx_add_to_hash(size_t hash, size_t i) {
-	return ISC_ROTATE_LEFT(hash, 5) ^ i * K;
+	return (ISC_ROTATE_LEFT(hash, 5) ^ i) * K;
 }
 
 /*