diff --git a/src/Rlp/Lex.x b/src/Rlp/Lex.x
index 848983f..18592f8 100644
--- a/src/Rlp/Lex.x
+++ b/src/Rlp/Lex.x
@@ -115,7 +115,7 @@ alexGetByte inp = case inp ^. aiBytes of
                        & aiPrevChar .~ c
                        -- update the position
                        & aiPos %~ \ (ln,col) ->
-                                   if (inp ^. aiPrevChar) == '\n'
+                                   if c == '\n'
                                    then (ln+1,1)
                                    else (ln,col+1)
         pure (b, inp')