diff --git a/models b/models
index 82094fab7..d36a1e4c2 100644
--- a/models
+++ b/models
@@ -68,7 +68,7 @@ Course
     hasRegistration Bool -- canRegisterNow = hasRegistration && maybe False (<= currentTime) registerFrom && maybe True (>= currentTime) registerTo
     registerFrom UTCTime Maybe
     registerTo   UTCTime Maybe
-    CourseTermShort termId shorthand 
+    CourseTermShort termId shorthand
 Lecturer 
     userId       UserId
     courseId     CourseId
diff --git a/src/Handler/Course.hs b/src/Handler/Course.hs
index d287e2da4..742abd7b1 100644
--- a/src/Handler/Course.hs
+++ b/src/Handler/Course.hs
@@ -198,28 +198,52 @@ courseEditHandler course = do
                     })) -> do -- edit existing course
           let tident = unTermKey tid
           actTime <- liftIO getCurrentTime
-          addMessage "info" [shamlet| #{show res}|]
+          addMessage "debug" [shamlet| #{show res}|]
           runDB $ do
+            old <- get cid
+            case old of
+              Nothing -> addMessageI "error" $ MsgInvalidInput
+              (Just oldCourse) -> do
             -- existing <- getBy $ CourseTermShort tid csh
             -- if ((entityKey <$> existing) /= Just cid)
             --  then addMessageI "danger" $ MsgCourseEditDupShort tident csh
             --   else do
-                addMessage "info" $ fromMaybe [shamlet|No description given.|] $ cfDesc res
-                update cid
-                  [ CourseName         =. cfName     res
-                  , CourseDescription  =. cfDesc     res
-                  , CourseLinkExternal =. cfLink     res
-                  , CourseShorthand    =. cfShort    res -- TODO: change here should generate a warning, or only allowed for Admins?!
-                  , CourseTermId       =. tid            -- TODO: change here should generate a warning, or only allowed for Admins?!
-                  , CourseSchoolId     =. cfSchool   res
-                  , CourseCapacity     =. cfCapacity res
-                  , CourseRegisterFrom =. cfRegFrom  res
-                  , CourseRegisterTo   =. cfRegTo    res
-                  , CourseChangedBy    =. aid
-                  , CourseChanged      =. actTime
-                  ]
+                addMessage "debug" $ fromMaybe [shamlet|No description given.|] $ cfDesc res
+--                 update cid
+--                   [ CourseName         =. cfName     res
+--                   , CourseDescription  =. cfDesc     res
+--                   , CourseLinkExternal =. cfLink     res
+--                   , CourseShorthand    =. cfShort    res -- TODO: change here should generate a warning, or only allowed for Admins?!
+--                   , CourseTermId       =. tid            -- TODO: change here should generate a warning, or only allowed for Admins?!
+--                   , CourseSchoolId     =. cfSchool   res
+--                   , CourseCapacity     =. cfCapacity res
+--                   , CourseRegisterFrom =. cfRegFrom  res
+--                   , CourseRegisterTo   =. cfRegTo    res
+--                   , CourseChangedBy    =. aid
+--                   , CourseChanged      =. actTime
+--                   ]
+                updOkay <- replace cid (  -- TODO replaceUnique requires Eq?!
+                    Course { courseName            = cfName     res
+                           , courseDescription     = cfDesc     res
+                           , courseLinkExternal    = cfLink     res
+                           , courseShorthand       = cfShort    res
+                           , courseTermId          = cfTerm     res
+                           , courseSchoolId        = cfSchool   res
+                           , courseCapacity        = cfCapacity res
+                           , courseChanged         = actTime
+                           , courseChangedBy       = aid
+                           , courseCreated         = courseCreated   oldCourse
+                           , courseCreatedBy       = courseCreatedBy oldCourse
+                           , courseHasRegistration = cfHasReg   res
+                           , courseRegisterFrom    = cfRegFrom  res
+                           , courseRegisterTo      = cfRegTo    res
+                    }
+                  )
+--                 if (isNothing updOkay)
+--                   then do
                 addMessageI "info" $ MsgCourseEditOk tident csh
                 redirect $ CourseListTermR tid
+--                   else addMessageI "danger" $ MsgCourseEditDupShort tident csh
 
       (FormFailure _) -> addMessageI "warning" MsgInvalidInput
       other -> addMessage "error" $ [shamlet| Error: #{show other}|]
diff --git a/templates/default-layout.lucius b/templates/default-layout.lucius
index cc0884a30..cfdb85a35 100644
--- a/templates/default-layout.lucius
+++ b/templates/default-layout.lucius
@@ -71,3 +71,8 @@
 #message {
     margin-bottom: 40px;
 }
+
+.alert-debug {
+  background-color: rgb(240, 30, 240);
+}
+