diff --git a/examples/ASTEditor.hs b/examples/ASTEditor.hs
--- a/examples/ASTEditor.hs
+++ b/examples/ASTEditor.hs
@@ -27,6 +27,7 @@
   do
     intro
     hSetBuffering stdin NoBuffering
+    hSetBuffering stdout NoBuffering
     loop $ enter Expr example
 
 example = Let (Seq ["x" := Mul (Const 6) (Const 9), "y" := Const (-12)])
diff --git a/examples/ASTUse.hs b/examples/ASTUse.hs
--- a/examples/ASTUse.hs
+++ b/examples/ASTUse.hs
@@ -5,6 +5,7 @@
 {-# LANGUAGE TypeOperators         #-}
 {-# LANGUAGE TypeSynonymInstances  #-}
 {-# LANGUAGE EmptyDataDecls        #-}
+{-# LANGUAGE FlexibleInstances     #-}
 
 module ASTUse where
 
diff --git a/zipper.cabal b/zipper.cabal
--- a/zipper.cabal
+++ b/zipper.cabal
@@ -1,5 +1,5 @@
 name:                   zipper
-version:                0.4.1
+version:                0.4.2
 license:                BSD3
 license-file:           LICENSE
 author:	                Alexey Rodriguez,