diff --git a/packages/storage/src/index.ts b/packages/storage/src/index.ts
index 76e438251..790d4337f 100644
--- a/packages/storage/src/index.ts
+++ b/packages/storage/src/index.ts
@@ -749,6 +749,12 @@ export interface WxtStorage {
     key: StorageItemKey,
     options: WxtStorageItemOptions<TValue> & { defaultValue: TValue },
   ): WxtStorageItem<TValue, TMetadata>;
+  defineItem<TValue, TMetadata extends Record<string, unknown> = {}>(
+    key: StorageItemKey,
+    options: WxtStorageItemOptions<TValue> & {
+      init: () => TValue | Promise<TValue>;
+    },
+  ): WxtStorageItem<TValue, TMetadata>;
   defineItem<TValue, TMetadata extends Record<string, unknown> = {}>(
     key: StorageItemKey,
     options: WxtStorageItemOptions<TValue>,