diff --git a/types/log4js.d.ts b/types/log4js.d.ts
index 7462574..9d080a3 100644
--- a/types/log4js.d.ts
+++ b/types/log4js.d.ts
@@ -302,7 +302,7 @@ export class Logger {
   isErrorEnabled(): boolean;
   isFatalEnabled(): boolean;
 
-  _log(level: string, data: any): void;
+  _log(level: Level, data: any): void;
 
   addContext(key: string, value: any): void;