diff --git a/examples/passing/Guards.purs b/examples/passing/Guards.purs
--- a/examples/passing/Guards.purs
+++ b/examples/passing/Guards.purs
@@ -20,4 +20,10 @@
     _ | m < n     -> n
       | otherwise -> m
 
+  testIndentation :: Number -> Number -> Number
+  testIndentation x y | x > 0 
+    = x + y
+                      | otherwise 
+    = y - x
+
   main = Debug.Trace.trace $ min "Done" "ZZZZ"
diff --git a/examples/passing/Operators.purs b/examples/passing/Operators.purs
--- a/examples/passing/Operators.purs
+++ b/examples/passing/Operators.purs
@@ -61,6 +61,9 @@
   test15 :: Number -> Number -> Boolean
   test15 a b = const false $ a `test14` b
 
+  test16 :: Number -> Number -> Number 
+  test16 x y = x .|. y .&. y
+
   main = do
     let t1 = test1 1 2 (\x y -> x + y)
     let t2 = test2
@@ -77,4 +80,5 @@
     let t13 = test13 k 1 2
     let t14 = test14 1 2
     let t15 = test15 1 2
+    let t16 = test16 1 2
     trace "Done"
diff --git a/prelude/prelude.purs b/prelude/prelude.purs
--- a/prelude/prelude.purs
+++ b/prelude/prelude.purs
@@ -17,7 +17,7 @@
   , negate
   , Eq, (==), (/=), refEq, refIneq
   , Ord, Ordering(..), compare, (<), (>), (<=), (>=)
-  , Bits, (&), (|), (^), shl, shr, zshr, complement
+  , Bits, (.&.), (.|.), (.^.), shl, shr, zshr, complement
   , BoolLike, (&&), (||)
   , not
   , Semigroup, (<>), (++)
@@ -372,14 +372,14 @@
       EQ -> compare xs ys
       other -> other
 
-  infixl 10 &
-  infixl 10 |
-  infixl 10 ^
+  infixl 10 .&.
+  infixl 10 .|.
+  infixl 10 .^.
 
   class Bits b where
-    (&) :: b -> b -> b
-    (|) :: b -> b -> b
-    (^) :: b -> b -> b
+    (.&.) :: b -> b -> b
+    (.|.) :: b -> b -> b
+    (.^.) :: b -> b -> b
     shl :: b -> Number -> b
     shr :: b -> Number -> b
     zshr :: b -> Number -> b
@@ -426,9 +426,9 @@
                                \}" :: Number -> Number
 
   instance bitsNumber :: Bits Number where
-    (&) = numAnd
-    (|) = numOr
-    (^) = numXor
+    (.&.) = numAnd
+    (.|.) = numOr
+    (.^.) = numXor
     shl = numShl
     shr = numShr
     zshr = numZshr
diff --git a/psc-make/Main.hs b/psc-make/Main.hs
--- a/psc-make/Main.hs
+++ b/psc-make/Main.hs
@@ -19,7 +19,6 @@
 import Control.Applicative
 import Control.Monad.Error
 
-import Data.Bool (bool)
 import Data.Version (showVersion)
 
 import System.Console.CmdTheLine
@@ -41,7 +40,7 @@
 readInput :: InputOptions -> IO [(Either P.RebuildPolicy FilePath, String)]
 readInput InputOptions{..} = do
   content <- forM ioInputFiles $ \inputFile -> (Right inputFile, ) <$> U.readFile inputFile
-  return $ bool ((Left P.RebuildNever, P.prelude) :) id ioNoPrelude content
+  return (if ioNoPrelude then content else (Left P.RebuildNever, P.prelude) : content)
 
 newtype Make a = Make { unMake :: ErrorT String IO a } deriving (Functor, Applicative, Monad, MonadIO, MonadError String)
 
diff --git a/psc/Main.hs b/psc/Main.hs
--- a/psc/Main.hs
+++ b/psc/Main.hs
@@ -19,7 +19,6 @@
 import Control.Applicative
 import Control.Monad.Error
 
-import Data.Bool (bool)
 import Data.Maybe (fromMaybe)
 import Data.Version (showVersion)
 
@@ -43,7 +42,7 @@
 readInput InputOptions{..}
   | ioUseStdIn = return . (Nothing ,) <$> getContents
   | otherwise = do content <- forM ioInputFiles $ \inputFile -> (Just inputFile, ) <$> U.readFile inputFile
-                   return $ bool ((Nothing, P.prelude) :) id ioNoPrelude content
+                   return (if ioNoPrelude then content else (Nothing, P.prelude) : content)
 
 compile :: P.Options P.Compile -> Bool -> [FilePath] -> Maybe FilePath -> Maybe FilePath -> Bool -> IO ()
 compile opts stdin input output externs usePrefix = do
diff --git a/purescript.cabal b/purescript.cabal
--- a/purescript.cabal
+++ b/purescript.cabal
@@ -1,5 +1,5 @@
 name: purescript
-version: 0.6.1
+version: 0.6.1.1
 cabal-version: >=1.8
 build-type: Simple
 license: MIT
@@ -24,7 +24,7 @@
     location: https://github.com/purescript/purescript.git
 
 library
-    build-depends: base >=4 && <5,
+    build-depends: base >=4.6 && <5,
                    cmdtheline == 0.2.*,
                    containers -any,
                    unordered-containers -any,
diff --git a/src/Language/PureScript.hs b/src/Language/PureScript.hs
--- a/src/Language/PureScript.hs
+++ b/src/Language/PureScript.hs
@@ -42,7 +42,6 @@
 import Data.Function (on)
 import Data.Maybe (fromMaybe)
 import Data.FileEmbed (embedFile)
-import Data.Traversable (traverse)
 
 import Control.Monad.Error
 import Control.Arrow ((&&&))
@@ -142,6 +141,11 @@
   -- | Always rebuild this module
   | RebuildAlways deriving (Show, Eq, Ord)
 
+-- Traverse (Either e) instance (base 4.7)
+traverseEither :: Applicative f => (a -> f b) -> Either e a -> f (Either e b)
+traverseEither _ (Left x) = pure (Left x)
+traverseEither f (Right y) = Right <$> f y
+
 -- |
 -- Compiles in "make" mode, compiling each module separately to a js files and an externs file
 --
@@ -163,7 +167,7 @@
 
     jsTimestamp <- getTimestamp jsFile
     externsTimestamp <- getTimestamp externsFile
-    inputTimestamp <- traverse getTimestamp inputFile
+    inputTimestamp <- traverseEither getTimestamp inputFile
 
     return $ case (inputTimestamp, jsTimestamp, externsTimestamp) of
       (Right (Just t1), Just t2, Just t3) | t1 < min t2 t3 -> s
diff --git a/src/Language/PureScript/Constants.hs b/src/Language/PureScript/Constants.hs
--- a/src/Language/PureScript/Constants.hs
+++ b/src/Language/PureScript/Constants.hs
@@ -65,14 +65,14 @@
 (/=) :: String
 (/=) = "/="
 
-(&) :: String
-(&) = "&"
+(.&.) :: String
+(.&.) = ".&."
 
-bar :: String
-bar = "|"
+(.|.) :: String
+(.|.) = ".|."
 
-(^) :: String
-(^) = "^"
+(.^.) :: String
+(.^.) = ".^."
 
 (&&) :: String
 (&&) = "&&"
diff --git a/src/Language/PureScript/Optimizer/Inliner.hs b/src/Language/PureScript/Optimizer/Inliner.hs
--- a/src/Language/PureScript/Optimizer/Inliner.hs
+++ b/src/Language/PureScript/Optimizer/Inliner.hs
@@ -117,9 +117,9 @@
   , binaryFunction C.bitsNumber C.shl ShiftLeft
   , binaryFunction C.bitsNumber C.shr ShiftRight
   , binaryFunction C.bitsNumber C.zshr ZeroFillShiftRight
-  , binary         C.bitsNumber (C.&) BitwiseAnd
-  , binary         C.bitsNumber C.bar BitwiseOr
-  , binary         C.bitsNumber (C.^) BitwiseXor
+  , binary         C.bitsNumber (C..&.) BitwiseAnd
+  , binary         C.bitsNumber (C..|.) BitwiseOr
+  , binary         C.bitsNumber (C..^.) BitwiseXor
   , unary          C.bitsNumber C.complement BitwiseNot
 
   , binary C.boolLikeBoolean (C.&&) And
diff --git a/src/Language/PureScript/Parser/Common.hs b/src/Language/PureScript/Parser/Common.hs
--- a/src/Language/PureScript/Parser/Common.hs
+++ b/src/Language/PureScript/Parser/Common.hs
@@ -71,7 +71,7 @@
 -- A list of reserved operators
 --
 reservedOpNames :: [String]
-reservedOpNames = [ "=>", "->", "=", ".", "\\" ]
+reservedOpNames = [ "=>", "->", "=", ".", "\\", "|" ]
 
 -- |
 -- Valid first characters for an identifier
diff --git a/src/Language/PureScript/Parser/Declarations.hs b/src/Language/PureScript/Parser/Declarations.hs
--- a/src/Language/PureScript/Parser/Declarations.hs
+++ b/src/Language/PureScript/Parser/Declarations.hs
@@ -83,9 +83,9 @@
   name <- parseIdent
   binders <- P.many parseBinderNoParens
   value <- Left <$> (C.indented *>
-                       C.mark (P.many1 ((,) <$> (C.same *> parseGuard)
-                                            <*> (lexeme (indented *> P.char '=') *> parseValueWithWhereClause)
-                                       )))
+                       P.many1 ((,) <$> parseGuard
+                                    <*> (lexeme (indented *> P.char '=') *> parseValueWithWhereClause)
+                               ))
        <|> Right <$> (lexeme (indented *> P.char '=') *> parseValueWithWhereClause)
   return $ ValueDeclaration name Value binders value
   where
@@ -304,9 +304,9 @@
 parseCaseAlternative :: P.Parsec String ParseState CaseAlternative
 parseCaseAlternative = CaseAlternative <$> (return <$> parseBinder)
                                        <*> (Left <$> (C.indented *>
-                                                        C.mark (P.many1 ((,) <$> (C.same *> parseGuard)
-                                                                             <*> (lexeme (indented *> C.reservedOp "->") *> parseValue)
-                                                                        )))
+                                                        P.many1 ((,) <$> parseGuard
+                                                                     <*> (lexeme (indented *> C.reservedOp "->") *> parseValue)
+                                                                ))
                                             <|> Right <$> (lexeme (indented *> C.reservedOp "->") *> parseValue))
                                        P.<?> "case alternative"
 
diff --git a/src/Language/PureScript/Sugar/CaseDeclarations.hs b/src/Language/PureScript/Sugar/CaseDeclarations.hs
--- a/src/Language/PureScript/Sugar/CaseDeclarations.hs
+++ b/src/Language/PureScript/Sugar/CaseDeclarations.hs
@@ -19,7 +19,6 @@
     desugarCasesModule
 ) where
 
-import Data.Either (isLeft)
 import Data.Monoid ((<>))
 import Data.List (nub, groupBy)
 
@@ -34,6 +33,11 @@
 import Language.PureScript.Supply
 import Language.PureScript.Traversals
 import Language.PureScript.TypeChecker.Monad (guardWith)
+
+-- Data.Either.isLeft (base 4.7)
+isLeft :: Either a b -> Bool
+isLeft (Left _) = True
+isLeft (Right _) = False
 
 -- |
 -- Replace all top-level binders in a module with case expressions.