diff --git a/haskell-exp-parser.cabal b/haskell-exp-parser.cabal
--- a/haskell-exp-parser.cabal
+++ b/haskell-exp-parser.cabal
@@ -1,5 +1,5 @@
 name:           haskell-exp-parser
-version:        0.1.1
+version:        0.1.2
 synopsis:       Simple parser parser from Haskell to TemplateHaskell expressions
 description:    This package defines a simple parser for a subset of Haskell expressions and patterns to the TemplateHaskell AST.
                 .
@@ -53,12 +53,13 @@
 
   hs-source-dirs: tests
 
-  main-is: Splice.hs
+  main-is: ParseExp.hs
 
   default-language: Haskell2010
 
   build-depends:
     base,
     haskell-exp-parser,
+    syb,
     template-haskell
 
diff --git a/src/Language/Haskell/ParseExp.hs b/src/Language/Haskell/ParseExp.hs
--- a/src/Language/Haskell/ParseExp.hs
+++ b/src/Language/Haskell/ParseExp.hs
@@ -100,8 +100,8 @@
           <++ list
           <++ literal first
           <++ tuple
-  -- Must handle lists before literals, because the "['a']" is accepted as a
-  -- String literal
+  -- Must handle lists before literals, because "['a']" is accepted as a string
+  -- literal
 
 -- | Expression parser
 expression :: ReadP Exp
@@ -117,13 +117,13 @@
 parseExp :: String -> Either String Exp
 parseExp str = case [expr | (expr,"") <- readP_to_S expression str] of
     [expr] -> return expr
-    _ -> fail $ "parseExp: cannot parse '" ++ str ++ "'"
+    _ -> Left $ "parseExp: cannot parse '" ++ str ++ "'"
              ++ " (parseExp only supports a limited subset of Haskell)"
 
 -- | Parse a Haskell pattern (the supported subset is given above)
 parsePat :: String -> Either String Pat
 parsePat str = case [pat | (pat,"") <- readP_to_S name str] of
     [pat] -> return (VarP pat)
-    _ -> fail $ "parsePat: cannot parse '" ++ str ++ "'"
+    _ -> Left $ "parsePat: cannot parse '" ++ str ++ "'"
              ++ " (parsePat only supports a limited subset of Haskell)"
 
diff --git a/tests/ParseExp.hs b/tests/ParseExp.hs
--- a/tests/ParseExp.hs
+++ b/tests/ParseExp.hs
@@ -1,22 +1,58 @@
-module ParseExp where
-
-
+{-# LANGUAGE TemplateHaskell #-}
 
+import Data.Data
 import Data.Either
+import Data.Generics.Aliases
+import Data.Generics.Schemes
 import Language.Haskell.TH
+import System.Exit
 
 import Language.Haskell.ParseExp
 
 
 
-parse :: String -> ExpQ
-parse str = return $ case parseExp str of
-    Right exp -> exp
+fixNegLits :: Exp -> Exp
+fixNegLits = everywhere (mkT trans)
+  where
+    trans (LitE (IntegerL l))
+        | l < 0 = AppE (VarE (mkName "negate")) (LitE (IntegerL (negate l)))
+    trans e = e
+
+parse :: String -> Exp
+parse str = case parseExp str of
+    Right exp -> fixNegLits exp
     Left msg  -> error msg
 
-exp1 = parse "\"sdf\""
-exp2 = parse "sum [1,2,3]"
-exp3 = parse "min (max (negate (-34)) 888) (signum (-45))"
-exp4 = parse "  min   (  max   (  negate   (  -  34  )  )   888  )   (   signum    (  - 45   )   )  "
-exp5 = parse "[(1,'a'),(2,'b'),(3,'c')]"
+dequalify :: Exp -> Exp
+dequalify = everywhere (mkT trans)
+  where
+    trans (VarE v) = VarE $ mkName $ nameBase v
+    trans e        = e
+
+addWhite :: Char -> String
+addWhite c
+    | c `elem` cs = "   " ++ [c] ++ "   "
+    | otherwise   = [c]
+  where
+    cs = ['(', ')', ',', '-', ' ']
+
+test1 = ("\"sdf\"",                                      [| "sdf" |])
+test2 = ("sum [1,2,3]",                                  [| sum [1,2,3] |])
+test3 = ("min (max (negate (-34)) 888) (signum (-45))",  [| min (max (negate (-34)) 888) (signum (-45)) |])
+test4 = ("[(1,'a',\"a\"),(2,'b',\"b\"),(-3,'c',\"c\")]", [| [(1,'a',"a"),(2,'b',"b"),(-3,'c',"c")] |])
+
+tests = [test1,test2,test3,test4]
+
+main = do
+    es1 <- mapM (fmap dequalify . runQ . snd) tests
+    let es2  = map (parse . fst) tests
+        es3  = map (parse . concatMap addWhite . fst) tests
+        oks2 = map (uncurry (==)) $ zip es1 es2
+        oks3 = map (uncurry (==)) $ zip es1 es3
+        failedTests = [i | (i,(ok2,ok3)) <- zip [1..] (zip oks2 oks3), not (ok2&&ok3)]
+    if and oks2 && and oks3
+    then putStrLn "All tests passed"
+    else do
+      putStrLn $ "Tests " ++ show failedTests ++ " failed"
+      exitFailure
 
diff --git a/tests/Splice.hs b/tests/Splice.hs
deleted file mode 100644
--- a/tests/Splice.hs
+++ /dev/null
@@ -1,24 +0,0 @@
-{-# LANGUAGE TemplateHaskell #-}
-
-import System.Exit
-
-import ParseExp
-
-
-
-tests =
-    [ (show ($exp1), show "sdf")
-    , (show ($exp2), show (sum [1,2,3]))
-    , (show ($exp3), show (min (max (negate (-34)) 888) (signum (-45))))
-    , (show ($exp4), show (  min   (  max   (  negate   (  -  34  )  )   888  )   (   signum    (  - 45   )   )  ))
-    , (show ($exp5), show ([(1,'a'),(2,'b'),(3,'c')]))
-    ]
-
-main = if and oks
-    then putStrLn "All tests passed"
-    else do
-      putStrLn $ "Tests " ++ show [i | (i,False) <- zip [1..] oks] ++ " failed"
-      exitFailure
-  where
-    oks = map (uncurry (==)) tests
-