diff --git a/core/stores/redis/conf.go b/core/stores/redis/conf.go
index 00a7ff3d0..bdf9afefe 100644
--- a/core/stores/redis/conf.go
+++ b/core/stores/redis/conf.go
@@ -25,7 +25,7 @@ type (
 	// A RedisKeyConf is a redis config with key.
 	RedisKeyConf struct {
 		RedisConf
-		Key string `json:",optional"`
+		Key string
 	}
 )