diff --git a/src/Vervis/Migration.hs b/src/Vervis/Migration.hs
index b78bc60..9b970ec 100644
--- a/src/Vervis/Migration.hs
+++ b/src/Vervis/Migration.hs
@@ -2539,8 +2539,11 @@ changes hLocal ctx =
         (Just $ \ (Entity topicTemp (CollabTopicLocal447 collabTemp)) -> do
             collabs <- selectList [] []
             for_ collabs $ \ (Entity topicID topic) -> do
+                maybeLocal <- getKeyBy $ UniqueCollabTopicLocal447 $ collabTopicLocalAccept447Collab topic
                 localID <-
-                    insert $ CollabTopicLocal447 $ collabTopicLocalAccept447Collab topic
+                    case maybeLocal of
+                        Nothing -> error "No CollabTopicLocal for this Collab"
+                        Just l -> return l
                 update topicID [CollabTopicLocalAccept447CollabNew =. localID]
 
             delete topicTemp