diff --git a/hash.c b/hash.c
index 38440f4b96..b4b077fada 100644
--- a/hash.c
+++ b/hash.c
@@ -5656,9 +5656,10 @@ static void
 keylist_delete(VALUE keys, VALUE key)
 {
     long keylen, elen;
+    long i;
     const char *keyptr, *eptr;
     RSTRING_GETMEM(key, keyptr, keylen);
-    for (long i=0; i<RARRAY_LEN(keys); i++) {
+    for (i=0; i<RARRAY_LEN(keys); i++) {
         VALUE e = RARRAY_AREF(keys, i);
         RSTRING_GETMEM(e, eptr, elen);
         if (elen != keylen) continue;