diff --git a/Examples/MuFeldspar/Core.hs b/Examples/MuFeldspar/Core.hs
--- a/Examples/MuFeldspar/Core.hs
+++ b/Examples/MuFeldspar/Core.hs
@@ -1,6 +1,8 @@
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE GADTs #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE TypeFamilies #-}
 {-# LANGUAGE TypeOperators #-}
 {-# LANGUAGE TypeSynonymInstances #-}
 {-# LANGUAGE UndecidableInstances #-}
diff --git a/Language/Syntactic/Features/Binding.hs b/Language/Syntactic/Features/Binding.hs
--- a/Language/Syntactic/Features/Binding.hs
+++ b/Language/Syntactic/Features/Binding.hs
@@ -65,15 +65,18 @@
     -> AST (Lambda :+: Variable :+: dom) b
     -> Reader [(VarId,VarId)] Bool
 
-eqLambdaM (project -> Just (Variable v1)) (project -> Just (Variable v2)) = do
+-- eqLambdaM (project -> Just (Variable v1)) (project -> Just (Variable v2)) = do  -- Not accepted by GHC-6.12
+eqLambdaM (Symbol (InjectR (InjectL (Variable v1)))) (Symbol (InjectR (InjectL (Variable v2)))) = do
     env <- ask
     case lookup v1 env of
       Nothing  -> return (v1==v2)   -- Free variables
       Just v2' -> return (v2==v2')
 
 eqLambdaM
-    ((project -> Just (Lambda v1)) :$: a1)
-    ((project -> Just (Lambda v2)) :$: a2)
+--     ((project -> Just (Lambda v1)) :$: a1)
+--     ((project -> Just (Lambda v2)) :$: a2)  -- Not accepted by GHC-6.12
+    (Symbol (InjectL (Lambda v1)) :$: a1)
+    (Symbol (InjectL (Lambda v2)) :$: a2)
       = local ((v1,v2):) $ eqLambdaM a1 a2
 
 eqLambdaM (f1 :$: a1) (f2 :$: a2) = do
@@ -103,7 +106,8 @@
   where
     eval :: (Eval dom, MonadReader [(VarId,Dynamic)] m) =>
         AST (Lambda :+: Variable :+: dom) a -> m a
-    eval (project -> Just (Variable v)) = do
+--     eval (project -> Just (Variable v)) = do  -- Not accepted by GHC-6.12
+    eval (Symbol (InjectR (InjectL (Variable v)))) = do
         env <- ask
         case lookup v env of
           Nothing -> return $ error "eval: evaluating free variable"
@@ -111,7 +115,8 @@
             Just a -> return (Full a)
             _      -> return $ error "eval: internal type error"
 
-    eval ((project -> Just (Lambda v)) :$: body) = do
+--     eval ((project -> Just (Lambda v)) :$: body) = do  -- Not accepted by GHC-6.12
+    eval (Symbol (InjectL (Lambda v)) :$: body) = do
         env <- ask
         return
             $ Full
diff --git a/syntactic.cabal b/syntactic.cabal
--- a/syntactic.cabal
+++ b/syntactic.cabal
@@ -1,5 +1,5 @@
 Name:           syntactic
-Version:        0.2
+Version:        0.2.0.1
 Synopsis:       Generic abstract syntax, and utilities for embedded languages
 Description:    This library provides:
                 .