diff --git a/src/t_zset.c b/src/t_zset.c
index bc947c9658..dd0678f7ac 100644
--- a/src/t_zset.c
+++ b/src/t_zset.c
@@ -120,8 +120,9 @@ void zslFree(zskiplist *zsl) {
  * (both inclusive), with a powerlaw-alike distribution where higher
  * levels are less likely to be returned. */
 int zslRandomLevel(void) {
+    static const int threshold = ZSKIPLIST_P*RAND_MAX;
     int level = 1;
-    while ((random()&0xFFFF) < (ZSKIPLIST_P * 0xFFFF))
+    while (random() < threshold)
         level += 1;
     return (level<ZSKIPLIST_MAXLEVEL) ? level : ZSKIPLIST_MAXLEVEL;
 }