diff --git a/convlab2/policy/vector/vector_binary.py b/convlab2/policy/vector/vector_binary.py
index ba4f789e6484384bbb5f689654b992e41a717b34..1f64b1a3de4aab39b8f1814cd1ecaefcfb13057e 100755
--- a/convlab2/policy/vector/vector_binary.py
+++ b/convlab2/policy/vector/vector_binary.py
@@ -68,7 +68,7 @@ class VectorBinary(VectorBase):
         domain_mask = self.compute_domain_mask(domain_active_dict)
         entity_mask = self.compute_entity_mask(number_entities_dict)
         general_mask = self.compute_general_mask()
-        mask = domain_mask + entity_mask + general_mask
+        mask = entity_mask + general_mask
         return mask
 
     def vectorize_booked(self, state):