diff --git a/importer/Frame.py b/importer/Frame.py
index 94649def96015b3c688d6233c1ffab8eb3b0816b..d72862672f7924a4f9713f0d205a95dd91044adc 100644
--- a/importer/Frame.py
+++ b/importer/Frame.py
@@ -29,6 +29,8 @@ class Frame:
             arguments = {}
             id = frame_tree._attrs['xml:id']
             opinion = frame_tree._children[0]._children[0]._attrs['value']
+            if opinion == 'unk':
+                opinion = 'cer'
             meanings = [meaning._attrs['sameAs'][1:] for meaning in frame_tree._children[1]._children[0]._children]
             for argument_tree in frame_tree._children[2]._children[0]._children:
                 argument = Argument.fromTree(argument_tree)