diff --git a/src/Data/Biunfoldable.hs b/src/Data/Biunfoldable.hs
--- a/src/Data/Biunfoldable.hs
+++ b/src/Data/Biunfoldable.hs
@@ -10,6 +10,7 @@
 --
 -- Class of data structures with 2 type arguments that can be unfolded.
 -----------------------------------------------------------------------------
+{-# LANGUAGE Safe #-}
 module Data.Biunfoldable 
   (
 
diff --git a/src/Data/Triunfoldable.hs b/src/Data/Triunfoldable.hs
--- a/src/Data/Triunfoldable.hs
+++ b/src/Data/Triunfoldable.hs
@@ -10,6 +10,7 @@
 --
 -- Class of data structures with 3 type arguments that can be unfolded.
 -----------------------------------------------------------------------------
+{-# LANGUAGE Safe #-}
 module Data.Triunfoldable 
   (
 
diff --git a/src/Data/Unfoldable.hs b/src/Data/Unfoldable.hs
--- a/src/Data/Unfoldable.hs
+++ b/src/Data/Unfoldable.hs
@@ -10,6 +10,7 @@
 --
 -- Class of data structures that can be unfolded.
 -----------------------------------------------------------------------------
+{-# LANGUAGE Safe #-}
 module Data.Unfoldable 
   (
   
diff --git a/src/Data/Unfolder.hs b/src/Data/Unfolder.hs
--- a/src/Data/Unfolder.hs
+++ b/src/Data/Unfolder.hs
@@ -17,6 +17,7 @@
     ScopedTypeVariables
   , GeneralizedNewtypeDeriving
   , RankNTypes
+  , Trustworthy
   #-}
 module Data.Unfolder 
   (
diff --git a/unfoldable.cabal b/unfoldable.cabal
--- a/unfoldable.cabal
+++ b/unfoldable.cabal
@@ -1,5 +1,5 @@
 Name:                 unfoldable
-Version:              0.6.0.2
+Version:              0.6.1
 Synopsis:             Class of data structures that can be unfolded.
 Description:          Just as there's a Foldable class, there should also be an Unfoldable class. 
                       .