diff --git a/src/config.ts b/src/config.ts
index e68927b7..b38f93a3 100644
--- a/src/config.ts
+++ b/src/config.ts
@@ -105,7 +105,7 @@ export interface MLCEngineConfig {
   appConfig?: AppConfig;
   initProgressCallback?: InitProgressCallback;
   logitProcessorRegistry?: Map<string, LogitProcessor>;
-  logLevel: LogLevel;
+  logLevel?: LogLevel;
 }
 
 /**