diff --git a/src/sentinel.c b/src/sentinel.c
index 7b703aa331d..f0901eeb61e 100644
--- a/src/sentinel.c
+++ b/src/sentinel.c
@@ -459,6 +459,7 @@ struct redisCommand sentinelcmds[] = {
  * specific defaults. */
 void initSentinelConfig(void) {
     server.port = REDIS_SENTINEL_PORT;
+    server.protected_mode = 0; /* Sentinel must be exposed. */
 }
 
 /* Perform the Sentinel mode initialization. */