diff --git a/app/service/outfit_matcher/dataset.py b/app/service/outfit_matcher/dataset.py
index 6e11983..4718688 100644
--- a/app/service/outfit_matcher/dataset.py
+++ b/app/service/outfit_matcher/dataset.py
@@ -59,7 +59,7 @@ class FashionDataset(object):
         if given_cate == 'tops' or given_cate == "bottoms":
             complementary_cate = "bottoms" if given_cate == "tops" else "tops"
             # check bottom num
-            if not self.cate2num[complementary_cate]:
+            if complementary_cate not in self.cate2num.keys() or not self.cate2num[complementary_cate]:
                 raise ValueError(f"Not enough {complementary_cate} available to generate outfits.")
 
             complementary_items = deepcopy(self.cate2item[complementary_cate])