--- a/src/pyams_content/component/gallery/zmi/file.py	Thu May 03 11:05:45 2018 +0200
+++ b/src/pyams_content/component/gallery/zmi/file.py	Thu May 03 11:29:56 2018 +0200
@@ -208,6 +208,8 @@
             self.widgets['pif_number'].input_css_class = 'col-md-3'
         if 'sound_description' in self.widgets:
             self.widgets['sound_description'].widget_css_class = 'textarea'
+            
+    def updateGroups(self):
         self.add_group(NamedWidgetsGroup(self, 'audio_file', self.widgets,
                                          ('sound', 'sound_title', 'sound_description'),
                                          bordered=False,
@@ -215,6 +217,7 @@
                                          css_class='inner',
                                          switch=True,
                                          hide_if_empty=True))
+        super(GalleryFilePropertiesEditForm, self).updateGroups()
 
 
 @view_config(name='gallery-file-properties.json', context=IGalleryFile, request_type=IPyAMSLayer,