diff --git a/src/Handler/Exam/AutoOccurrence.hs b/src/Handler/Exam/AutoOccurrence.hs
index 2715da603..28e5e0d4f 100644
--- a/src/Handler/Exam/AutoOccurrence.hs
+++ b/src/Handler/Exam/AutoOccurrence.hs
@@ -113,7 +113,7 @@ postEAutoOccurrenceR tid ssh csh examn = do
     let participants' = Map.fromList $ do
           (Entity uid userRec, Entity _ ExamRegistration{..}) <- participants
           return (uid, (userRec, examRegistrationOccurrence))
-        occurrences' = Map.fromList $ map (\(Entity eoId ExamOccurrence{..}) -> (eoId, fromIntegral examOccurrenceCapacity)) occurrences
+        occurrences' = Map.fromList $ map (\(Entity eoId ExamOccurrence{..}) -> (eoId, view (from _examOccurrenceCapacityIso) $ fromIntegral <$> examOccurrenceCapacity)) occurrences
         autoOccurrenceResult = examAutoOccurrence eId examOccurrenceRule eaofConfig occurrences' participants'
     (eaofMapping, eaofAssignment) <- case autoOccurrenceResult of
       (Left e) -> do
@@ -165,8 +165,10 @@ postEAutoOccurrenceR tid ssh csh examn = do
               occMappingRule = examOccurrenceMappingRule eaofMapping
 
               loadProp curr max'
-                | max' /= 0 = MsgProportion (toMessage curr) (toMessage max') (toRational curr / toRational max')
-                | otherwise = MsgProportionNoRatio (toMessage curr) (toMessage max')
+                | Just max'' <- max', max'' /= 0
+                = MsgProportion (toMessage curr) (toMessage max'') (toRational curr / toRational max'')
+                | otherwise
+                = MsgProportionNoRatio (toMessage curr) $ maybe "-" toMessage max'
 
               occMapping occId = examOccurrenceMappingDescriptionWidget occMappingRule <$> Map.lookup occId (examOccurrenceMappingMapping eaofMapping)
            in $(widgetFile "widgets/exam-occurrence-mapping")