diff --git a/Text/Parsec/Indent.hs b/Text/Parsec/Indent.hs
--- a/Text/Parsec/Indent.hs
+++ b/Text/Parsec/Indent.hs
@@ -3,7 +3,7 @@
     -- $doc
     
     -- * Types
-    IndentParserT, runIndent,
+    IndentParser, runIndent,
     -- * Blocks
     withBlock, withBlock', block,
     -- * Indentation Checking
@@ -12,14 +12,13 @@
     indentBrackets, indentAngles, indentBraces, indentParens,
     -- * Line Fold Chaining
     -- | Any chain using these combinators must used with 'withPos'
-    (<+/>), (<-/>), (<*/>)
+    (<+/>), (<-/>), (<*/>), (<?/>), Optional(..)
     ) where
-import Text.Parsec
+import Text.Parsec hiding (State)
 import Text.Parsec.Pos
 import Text.Parsec.Token
 import Control.Monad.State
 import Control.Concatenative
-import Debug.Trace
 
 -- $doc
 -- A module to construct indentation aware parsers. Many programming
@@ -48,25 +47,25 @@
 
 -- | Indentation sensitive parser type. Usually @ m @ will
 --   be @ Identity @ as with any @ ParsecT @
-type IndentParserT s u m a = ParsecT s u (StateT SourcePos m) a
+type IndentParser s u a = ParsecT s u (State SourcePos) a
     
--- | @ 'withBlock' f a b p @ parses @ a @ and optionally
---   @ b @ followed by an indented block of @ p @
---   , combining them with @ f @
-withBlock :: (Stream s (StateT SourcePos m) Char, Monad m) => (a -> [b] -> c) ->
-    IndentParserT s u m a -> IndentParserT s u m x -> IndentParserT s u m b -> IndentParserT s u m c
-withBlock f a b p = withPos $ do
+-- | @ 'withBlock' f a p @ parses @ a @
+--   followed by an indented block of @ p @
+--   combining them with @ f @
+withBlock :: (Stream s (State SourcePos) Char) => (a -> [b] -> c) ->
+    IndentParser s u a -> IndentParser s u b -> IndentParser s u c
+withBlock f a p = withPos $ do
     r1 <- a
-    r2 <- option [] (b >> indented >> block p)
+    r2 <- option [] (indented >> block p)
     return (f r1 r2)
 
 -- | Like 'withBlock', but throws away initial parse result
-withBlock' :: (Stream s (StateT SourcePos m) Char, Monad m) =>
-    IndentParserT s u m a -> IndentParserT s u m x -> IndentParserT s u m b -> IndentParserT s u m [b]
+withBlock' :: (Stream s (State SourcePos) Char) =>
+    IndentParser s u a -> IndentParser s u b -> IndentParser s u [b]
 withBlock' = withBlock (flip const)
 
 -- | Parses only when indented past the level of the reference
-indented :: (Stream s (StateT SourcePos m) Char, Monad m) => IndentParserT s u m ()
+indented :: (Stream s (State SourcePos) Char) => IndentParser s u ()
 indented = do
     pos <- getPosition
     s <- get
@@ -75,24 +74,24 @@
         return ()
 
 -- | Parses only when indented past the level of the reference or on the same line
-sameOrIndented :: (Stream s (StateT SourcePos m) Char, Monad m) => IndentParserT s u m ()
+sameOrIndented :: Stream s (State SourcePos) Char => IndentParser s u ()
 sameOrIndented = same <|> indented
 
 -- | Parses only on the same line as the reference
-same :: (Stream s (StateT SourcePos m) Char, Monad m) => IndentParserT s u m ()
+same :: (Stream s (State SourcePos) Char) => IndentParser s u ()
 same = do
     pos <- getPosition
     s <- get
     if biAp sourceLine (==) pos s then return () else parserFail "over one line"
     
 -- | Parses a block of lines at the same indentation level
-block :: (Stream s (StateT SourcePos m) Char, Monad m) => IndentParserT s u m a -> IndentParserT s u m [a]
+block :: (Stream s (State SourcePos) Char) => IndentParser s u a -> IndentParser s u [a]
 block p = withPos $ do
     r <- many1 (checkIndent >> p)
     return r
 
 -- | Parses using the current location for indentation reference
-withPos :: (Stream s (StateT SourcePos m) Char, Monad m) => IndentParserT s u m a -> IndentParserT s u m a
+withPos :: (Stream s (State SourcePos) Char) => IndentParser s u a -> IndentParser s u a
 withPos x = do
     a <- get
     p <- getPosition
@@ -100,43 +99,51 @@
     put a >> return r
 
 -- | Ensures the current indentation level matches that of the reference
-checkIndent :: (Stream s (StateT SourcePos m) Char, Monad m) => IndentParserT s u m ()
+checkIndent :: (Stream s (State SourcePos) Char) => IndentParser s u ()
 checkIndent = do
     s <- get
     p <- getPosition
     if biAp sourceColumn (==) p s then return () else parserFail "indentation doesn't match"
 
 -- | Run the result of an indentation sensitive parse
-runIndent :: Monad m => SourceName -> StateT SourcePos m a -> m a
-runIndent s = flip evalStateT (initialPos s)
+runIndent :: SourceName -> State SourcePos a -> a
+runIndent s = flip evalState (initialPos s)
 
 -- | '<+/>' is to indentation sensitive parsers what 'ap' is to monads
-(<+/>) :: (Stream s (StateT SourcePos m) Char, Monad m) =>
-    IndentParserT s u m (a -> b) -> IndentParserT s u m a -> IndentParserT s u m b
+(<+/>) :: (Stream s (State SourcePos) Char) =>
+    IndentParser s u (a -> b) -> IndentParser s u a -> IndentParser s u b
 a <+/> b = ap a (sameOrIndented >> b)
 
 -- | '<-/>' is like '<+/>', but doesn't apply the function to the parsed value
-(<-/>) :: (Stream s (StateT SourcePos m) Char, Monad m) =>
-    IndentParserT s u m a -> IndentParserT s u m b -> IndentParserT s u m a
+(<-/>) :: (Stream s (State SourcePos) Char) =>
+    IndentParser s u a -> IndentParser s u b -> IndentParser s u a
 a <-/> b = liftM2 const a (sameOrIndented >> b)
 
 -- | Like '<+/>' but applies the second parser many times
-(<*/>) :: (Stream s (StateT SourcePos m) Char, Monad m) =>
-    IndentParserT s u m ([a] -> b) -> IndentParserT s u m a -> IndentParserT s u m b
+(<*/>) :: (Stream s (State SourcePos) Char) =>
+    IndentParser s u ([a] -> b) -> IndentParser s u a -> IndentParser s u b
 a <*/> b = ap a (many (sameOrIndented >> b))
 
+-- | Datatype used to optional parsing
+data Optional s u a = Opt a (IndentParser s u a)
+
+-- | Like '<+/>' but applies the second parser optionally using the 'Optional' datatype
+(<?/>) :: (Stream s (State SourcePos) Char) =>
+    IndentParser s u (a -> b) -> (Optional s u a) -> IndentParser s u b
+(<?/>) a (Opt b c) = ap a (option b (sameOrIndented >> c))
+
 -- | parses with surrounding brackets
-indentBrackets :: (Stream s (StateT SourcePos m) Char, Monad m) => GenTokenParser s u (StateT SourcePos m) -> IndentParserT s u m a -> IndentParserT s u m a
+indentBrackets :: (Stream s (State SourcePos) Char) => GenTokenParser s u (State SourcePos) -> IndentParser s u a -> IndentParser s u a
 indentBrackets lexer p = withPos $ return id <-/> symbol lexer "[" <+/> p <-/> symbol lexer "]"
 
 -- | parses with surrounding angle brackets
-indentAngles :: (Stream s (StateT SourcePos m) Char, Monad m) => GenTokenParser s u (StateT SourcePos m) -> IndentParserT s u m a -> IndentParserT s u m a
+indentAngles :: (Stream s (State SourcePos) Char) => GenTokenParser s u (State SourcePos) -> IndentParser s u a -> IndentParser s u a
 indentAngles lexer p = withPos $ return id <-/> symbol lexer "<" <+/> p <-/> symbol lexer ">"
 
 -- | parses with surrounding braces
-indentBraces :: (Stream s (StateT SourcePos m) Char, Monad m) => GenTokenParser s u (StateT SourcePos m) -> IndentParserT s u m a -> IndentParserT s u m a
+indentBraces :: (Stream s (State SourcePos) Char) => GenTokenParser s u (State SourcePos) -> IndentParser s u a -> IndentParser s u a
 indentBraces lexer p = withPos $ return id <-/> symbol lexer "{" <+/> p <-/> symbol lexer "}"
 
 -- | parses with surrounding parentheses 
-indentParens :: (Stream s (StateT SourcePos m) Char, Monad m) => GenTokenParser s u (StateT SourcePos m) -> IndentParserT s u m a -> IndentParserT s u m a
+indentParens :: (Stream s (State SourcePos) Char) => GenTokenParser s u (State SourcePos) -> IndentParser s u a -> IndentParser s u a
 indentParens lexer p = withPos $ return id <-/> symbol lexer "(" <+/> p <-/> symbol lexer ")"
diff --git a/indents.cabal b/indents.cabal
--- a/indents.cabal
+++ b/indents.cabal
@@ -7,7 +7,7 @@
 -- The package version. See the Haskell package versioning policy
 -- (http://www.haskell.org/haskellwiki/Package_versioning_policy) for
 -- standards guiding when and how versions should be incremented.
-Version:             0.3.0
+Version:             0.3.1
 
 -- A short (one-line) description of the package.
 Synopsis:            indentation sensitive parser-combinators for parsec
@@ -51,7 +51,7 @@
   Exposed-modules:     Text.Parsec.Indent
   
   -- Packages needed in order to build this package.
-  Build-depends: parsec >= 3 && < 4, concatenative < 2, mtl < 2, base < 4.3
+  Build-depends: parsec >= 3 && < 4, concatenative < 2, mtl < 3 , base < 4.4
   
   -- Modules not exported by this package.
   -- Other-modules: