diff --git a/backend/functions/assembly/search.ts b/backend/functions/assembly/search.ts
index 2c099c4..a210b5d 100644
--- a/backend/functions/assembly/search.ts
+++ b/backend/functions/assembly/search.ts
@@ -45,7 +45,7 @@ export function recommendProductByCart(
 
   const normalizedVec = normalize(sumVec);
 
-  const cartProductIds = cart.items.map((item) => item.Product.id);
+  const cartProductIds = cart.items.map<string>((item) => item.Product.id);
 
   const semanticSearchRes = collections.searchByVector(
     consts.productNameCollection,