diff --git a/src/Language/Lambda/Parser.hs b/src/Language/Lambda/Parser.hs
index 2465d0f28420be2be139e1f5921dc6cdf50df625..18b84aeddd208671629e2ab7c0efdb44b4f39792 100644
--- a/src/Language/Lambda/Parser.hs
+++ b/src/Language/Lambda/Parser.hs
@@ -53,6 +53,7 @@ keyword :: String -> Parser ()
 keyword = void . lexeme . string
 
 doOperation "" = ""
+doOperation (x:'+':y:xs) = ubahKeChurch x ++ ubahKeChurch '+' ++ ubahKeChurch y ++ doOperation xs
 doOperation (x:xs) = ubahKeChurch x ++ doOperation xs
 
 ubahKeChurch :: Char -> [Char]