diff --git a/src/Model/Migration.hs b/src/Model/Migration.hs
index dd04ba1d7..296b933d0 100644
--- a/src/Model/Migration.hs
+++ b/src/Model/Migration.hs
@@ -527,7 +527,7 @@ customMigrations = Map.fromListWith (>>)
     , whenM (tableExists "exam") $ do
         oldVersion <- columnExists "exam" "grading_key"
         if
-          | oldVersion ->
+          | oldVersion -> do
             -- Major changes happend to the structure of exams without appropriate
             -- migration, try to remedy that here
             tableDropEmpty "exam_part_corrector"