diff --git a/convlab2/dst/dst.py b/convlab2/dst/dst.py
index b2f45fdd74c0c4d6752ef9605c3066877e3c131e..3f6db0d067e125839f907d42305808c1758707f2 100755
--- a/convlab2/dst/dst.py
+++ b/convlab2/dst/dst.py
@@ -20,7 +20,6 @@ class DST(Module):
         """
         pass
 
-    @abstractmethod
     def update_turn(self, sys_utt, user_utt):
         """ Update the internal dialog state variable with .