diff --git a/sentinel/sentinel.go b/sentinel/sentinel.go
index 70546b3..bb78866 100644
--- a/sentinel/sentinel.go
+++ b/sentinel/sentinel.go
@@ -164,7 +164,7 @@ func NewPool(cfg Config) *redis.Pool {
 				err = fmt.Errorf(
 					"master(%s) got by name '%s' is not redis master",
 					masterAddr, masterName)
-                logErrLogger.Output(2, err.String())
+                logErrLogger.Output(2, err.Error())
 				return nil, err
 			}