diff --git a/main.go b/main.go
index 4f89f04..209c85d 100644
--- a/main.go
+++ b/main.go
@@ -66,6 +66,8 @@ func Init(flags Option, splitSize int64) error {
 			fmt.Printf("logger: new: couldn't create event log file\n")
 			return err
 		}
+
+		logger.muEv = &sync.Mutex{}
 	}
 
 	// error file/dir
@@ -85,6 +87,8 @@ func Init(flags Option, splitSize int64) error {
 			fmt.Printf("logger: new: couldn't create error log file\n")
 			return err
 		}
+
+		logger.muEr = &sync.Mutex{}
 	}
 
 	return nil