1 files changed, 3 insertions, 1 deletions
diff --git a/missing/memcmp.c b/missing/memcmp.c
index 5b3ad3817a..9657e6c372 100644
--- a/missing/memcmp.c
+++ b/missing/memcmp.c
@@ -1,5 +1,6 @@
 /* public domain rewrite of memcmp(3) */
 
+#include "ruby/missing.h"
 #include <stddef.h>
 
 int
@@ -10,7 +11,8 @@ memcmp(const void *s1, const void *s2, size_t len)
     register int tmp;
 
     for (; len; --len) {
-	if (tmp = *a++ - *b++)
+	tmp = *a++ - *b++;
+	if (tmp)
 	    return tmp;
     }
     return 0;