diff --git a/data.py b/data.py
index e6ba0c4..9ada051 100644
--- a/data.py
+++ b/data.py
@@ -100,6 +100,8 @@ def get_class_one_hot(self, class_str):
         # Now one-hot it.
         label_hot = to_categorical(label_encoded, len(self.classes))
 
+        assert len(label_hot) == len(self.classes)
+
         return label_hot
 
     def split_train_test(self):