diff --git a/app/Main.hs b/app/Main.hs
index 4f3cb37..b0465b2 100644
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -36,7 +36,7 @@ puzzleTest p =
                             BL.fromStrict . encodeUtf8 . pp.solve <$> input
   where
     pt = show p.number
-    parseFile fp = maybe (fail "parse failure") pure . parseMaybe (p.parser <* eof) =<< T.readFile fp
+    parseFile fp = either (fail . ("parse failure: " <>) . errorBundlePretty) pure . runParser (p.parser <* eof) fp =<< T.readFile fp
 
 data Puzzle input = Puzzle
     { number :: Word