--- a/src/pyams_content/component/extfile/__init__.py	Wed Feb 07 14:44:35 2018 +0100
+++ b/src/pyams_content/component/extfile/__init__.py	Wed Feb 07 14:44:51 2018 +0100
@@ -229,7 +229,7 @@
     @data.setter
     def data(self, value):
         self._data = value
-        for data in value.values():
+        for data in self._data.values():
             if IImage.providedBy(data):
                 alsoProvides(data, IResponsiveImage)