diff --git a/bert4keras/layers.py b/bert4keras/layers.py
index e2b95cb5..c9171812 100644
--- a/bert4keras/layers.py
+++ b/bert4keras/layers.py
@@ -111,7 +111,7 @@ def arguments(self):
 
         @arguments.setter
         def arguments(self, value):
-            self._arguments = value
+            self._arguments = value or {}
 
     if not is_tf_keras:
         keras.engine.base_layer.Node = Node