diff --git a/src/sentinel.c b/src/sentinel.c
index 7b387ef83..a9d123ebc 100644
--- a/src/sentinel.c
+++ b/src/sentinel.c
@@ -3176,12 +3176,12 @@ void sentinelConfigSetCommand(client *c) {
     } else if (!strcasecmp(o->ptr, "sentinel-user")) {
         sdsfree(sentinel.sentinel_auth_user);
         sentinel.sentinel_auth_user = sdslen(val->ptr) == 0 ?
-            sdsdup(val->ptr) : NULL;
+            NULL : sdsdup(val->ptr);
         drop_conns = 1;
     } else if (!strcasecmp(o->ptr, "sentinel-pass")) {
         sdsfree(sentinel.sentinel_auth_pass);
         sentinel.sentinel_auth_pass = sdslen(val->ptr) == 0 ?
-            sdsdup(val->ptr) : NULL;
+            NULL : sdsdup(val->ptr);
         drop_conns = 1;
     } else {
         addReplyErrorFormat(c, "Invalid argument '%s' to SENTINEL CONFIG SET",