diff --git a/config/config.go b/config/config.go
index 9392eb797b95b..bb1d3daf94309 100644
--- a/config/config.go
+++ b/config/config.go
@@ -821,7 +821,7 @@ func (c *Config) Valid() error {
 	if c.Security.SkipGrantTable && !hasRootPrivilege() {
 		return fmt.Errorf("TiDB run with skip-grant-table need root privilege")
 	}
-	if _, ok := ValidStorage[c.Store]; !ok {
+	if !ValidStorage[c.Store] {
 		nameList := make([]string, 0, len(ValidStorage))
 		for k, v := range ValidStorage {
 			if v {