diff --git a/src/networking.c b/src/networking.c
index f269591c..e7879384 100644
--- a/src/networking.c
+++ b/src/networking.c
@@ -124,7 +124,8 @@ redisClient *createClient(int fd) {
  * data to the clients output buffers. If the function returns REDIS_ERR no
  * data should be appended to the output buffers. */
 int prepareClientToWrite(redisClient *c) {
-    if (c->flags & (REDIS_LUA_CLIENT|REDIS_MASTER)) return REDIS_OK;
+    if (c->flags & REDIS_LUA_CLIENT) return REDIS_OK;
+    if (c->flags & REDIS_MASTER) return REDIS_ERR;
     if (c->fd <= 0) return REDIS_ERR; /* Fake client */
     if (c->bufpos == 0 && listLength(c->reply) == 0 &&
         (c->replstate == REDIS_REPL_NONE ||