diff --git a/prim-uniq.cabal b/prim-uniq.cabal
--- a/prim-uniq.cabal
+++ b/prim-uniq.cabal
@@ -1,5 +1,5 @@
 name:                   prim-uniq
-version:                0.1
+version:                0.1.0.1
 stability:              provisional
 
 cabal-version:          >= 1.6
@@ -15,6 +15,11 @@
 description:            Opaque unique identifiers in primitive state monads 
                         and a GADT-like type using them as witnesses of type
                         equality.
+
+tested-with:            GHC == 7.2.1,
+                        GHC == 7.0.4,
+                        GHC == 6.12.3,
+                        GHC == 6.10.4
 
 source-repository head
   type:     git
diff --git a/src/Data/Unique/Prim.hs b/src/Data/Unique/Prim.hs
--- a/src/Data/Unique/Prim.hs
+++ b/src/Data/Unique/Prim.hs
@@ -1,3 +1,7 @@
+{-# LANGUAGE CPP #-}
+#if defined(__GLASGOW_HASKELL__) && __GLASGOW_HASKELL__ >= 702
+{-# LANGUAGE Trustworthy #-}
+#endif
 module Data.Unique.Prim
     ( Uniq, getUniq, RealWorld
     ) where
diff --git a/src/Data/Unique/Tag.hs b/src/Data/Unique/Tag.hs
--- a/src/Data/Unique/Tag.hs
+++ b/src/Data/Unique/Tag.hs
@@ -1,3 +1,7 @@
+{-# LANGUAGE CPP #-}
+#if defined(__GLASGOW_HASKELL__) && __GLASGOW_HASKELL__ >= 702
+{-# LANGUAGE Trustworthy #-}
+#endif
 module Data.Unique.Tag
     ( Tag
     , newTag