diff --git a/packages/wxt/src/types/index.ts b/packages/wxt/src/types/index.ts
index f6b952f1..a996fce7 100644
--- a/packages/wxt/src/types/index.ts
+++ b/packages/wxt/src/types/index.ts
@@ -1300,7 +1300,7 @@ export type WxtModuleOptions = Record<string, any>;
 
 export type WxtModuleSetup<TOptions extends WxtModuleOptions> = (
   wxt: Wxt,
-  moduleOptions: TOptions,
+  moduleOptions?: TOptions,
 ) => void | Promise<void>;
 
 export interface WxtModule<TOptions extends WxtModuleOptions> {