diff --git a/cornac/eval_methods/next_basket_evaluation.py b/cornac/eval_methods/next_basket_evaluation.py
index 99ce57d9a..2c697d5a5 100644
--- a/cornac/eval_methods/next_basket_evaluation.py
+++ b/cornac/eval_methods/next_basket_evaluation.py
@@ -327,9 +327,13 @@ def _split(self):
         test_users = safe_indexing(users, test_idx)
         val_users = safe_indexing(users, val_idx) if len(val_idx) > 0 else None
 
-        train_data = [tup for tup in self._data if tup[0] in train_users]
-        val_data = [tup for tup in self._data if tup[0] in val_users]
-        test_data = [tup for tup in self._data if tup[0] in test_users]
+        data_by_user = OrderedDict()
+        for tup in self._data:
+            data_by_user.setdefault(tup[0], [])
+            data_by_user[tup[0]].append(tup)
+        train_data = [tup for u in train_users for tup in data_by_user[u]]
+        val_data = [tup for u in val_users for tup in data_by_user[u]]
+        test_data = [tup for u in test_users for tup in data_by_user[u]]
         self.build(train_data=train_data, test_data=test_data, val_data=val_data)
 
     def _build_datasets(self, train_data, test_data, val_data=None):