diff --git a/Logic/Parse.hs b/Logic/Parse.hs
index f203fbe..b98744f 100644
--- a/Logic/Parse.hs
+++ b/Logic/Parse.hs
@@ -79,9 +79,9 @@ parseToken token = Parser parse
       | otherwise = Left $ expected (show token) input
 
 parseIf :: Show s => String -> (s -> Bool) -> Parser s s
-parseIf description check = Parser $ \input ->
-  case inputSeq input of
-    [] -> Left $ ParseError (inputPos input) "unexpected end of input"
+parseIf description check = Parser $ \input@(Input pos xs) ->
+  case xs of
+    [] -> Left $ ParseError pos "unexpected end of input"
     (char:chars)
-      | check char -> Right $ (char,) $ Input (inputPos input + 1) chars
+      | check char -> Right $ (char,) $ Input (pos + 1) chars
       | otherwise -> Left $ expected description input