diff --git a/src/dict.c b/src/dict.c
index 840aae8e4244c13dc6bf06413e6f90e292ce970b..f1a67730c1cd8c19918521e48836478313f17bce 100644
--- a/src/dict.c
+++ b/src/dict.c
@@ -251,7 +251,7 @@ int dictRehash(dict *d, int n) {
 
         /* Note that rehashidx can't overflow as we are sure there are more
          * elements because ht[0].used != 0 */
-        assert(d->ht[0].size > (unsigned)d->rehashidx);
+        assert(d->ht[0].size > (unsigned long)d->rehashidx);
         while(d->ht[0].table[d->rehashidx] == NULL) d->rehashidx++;
         de = d->ht[0].table[d->rehashidx];
         /* Move all the keys in this bucket from the old to the new hash HT */