diff --git a/output_file.go b/output_file.go
index 915711c..209d563 100644
--- a/output_file.go
+++ b/output_file.go
@@ -69,10 +69,8 @@ func NewFileOutput(pathTemplate string, config *FileOutputConfig) *FileOutput {
 			if o.closed {
 				break
 			}
-			o.mu.Lock()
 			o.updateName()
 			o.flush()
-			o.mu.Unlock()
 		}
 	}()