diff --git a/src/Handler/LMS/Userlist.hs b/src/Handler/LMS/Userlist.hs
index 73a04b422..35902b986 100644
--- a/src/Handler/LMS/Userlist.hs
+++ b/src/Handler/LMS/Userlist.hs
@@ -22,13 +22,13 @@ import Database.Esqueleto.Utils.TH
 
 data LmsUserlistTableCsv = LmsUserlistTableCsv
   { csvLULident  :: LmsIdent
-  , csvLULfailed :: Bool 
+  , csvLULfailed :: LmsBool 
   }
   deriving Generic
 makeLenses_ ''LmsUserlistTableCsv
 
 -- csv without headers -- TODO not yet supported
-instance Csv.ToRecord LmsUserlistTableCsv
+instance Csv.ToRecord   LmsUserlistTableCsv
 instance Csv.FromRecord LmsUserlistTableCsv
 
 -- csv with headers 
@@ -121,7 +121,7 @@ mkUserlistTable sid qsh qid = do
             dbtCsvDoEncode      = \() -> C.map (doEncode' . view _2)
             doEncode' = LmsUserlistTableCsv
               <$> view (_dbrOutput . _entityVal . _lmsUserlistIdent)
-              <*> view (_dbrOutput . _entityVal . _lmsUserlistFailed)
+              <*> view (_dbrOutput . _entityVal . _lmsUserlistFailed . _lmsBool)
         dbtCsvDecode = Just DBTCsvDecode {..}
           where
             dbtCsvRowKey = \LmsUserlistTableCsv{csvLULident} -> 
@@ -129,13 +129,13 @@ mkUserlistTable sid qsh qid = do
             dbtCsvComputeActions = \case -- shows a diff first
               DBCsvDiffNew{dbCsvNew} -> do 
                 yield $ LmsUserlistInsertData 
-                          { lmsUserlistInsertIdent  = csvLULident   dbCsvNew
-                          , lmsUserlistInsertFailed = csvLULfailed  dbCsvNew
+                          { lmsUserlistInsertIdent  =            csvLULident   dbCsvNew
+                          , lmsUserlistInsertFailed = lms2bool $ csvLULfailed  dbCsvNew
                           }
               DBCsvDiffExisting{dbCsvNew = LmsUserlistTableCsv{..}} -> do 
                 yield $ LmsUserlistUpdateData 
                           { lmsUserlistInsertIdent  = csvLULident 
-                          , lmsUserlistInsertFailed = csvLULfailed
+                          , lmsUserlistInsertFailed = csvLULfailed & lms2bool 
                           }
               DBCsvDiffMissing{} -> return () -- no deletion 
             dbtCsvClassifyAction = \case 
diff --git a/src/Model/Types/Lms.hs b/src/Model/Types/Lms.hs
index d62851469..13d2ae183 100644
--- a/src/Model/Types/Lms.hs
+++ b/src/Model/Types/Lms.hs
@@ -36,3 +36,28 @@ deriveJSON  defaultOptions
   , sumEncoding = TaggedObject "lmsaudit" "lmsaction"
   } ''LmsStatus
 derivePersistFieldJSON ''LmsStatus
+
+
+-- LMS Interface requires Bool to be encoded by 0 or 1 only
+data LmsBool = LmsUnset | LmsSet 
+  deriving (Eq, Ord, Read, Show, Generic, Typeable, NFData)
+  
+lms2bool :: LmsBool -> Bool
+lms2bool LmsUnset = False 
+lms2bool LmsSet   = True 
+bool2lms :: Bool -> LmsBool
+bool2lms False = LmsUnset
+bool2lms True  = LmsSet
+
+_lmsBool :: Iso' Bool LmsBool
+_lmsBool = iso bool2lms lms2bool
+
+instance Csv.ToField LmsBool where 
+  toField LmsUnset = "0"
+  toField LmsSet   = "1"
+  
+instance Csv.FromField LmsBool where 
+  parseField i
+    | i == "0"  = pure LmsUnset
+    | i == "1"  = pure LmsSet
+    | otherwise = empty