diff --git a/Control/Concurrent/Thread.hs b/Control/Concurrent/Thread.hs
--- a/Control/Concurrent/Thread.hs
+++ b/Control/Concurrent/Thread.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE CPP, NoImplicitPrelude, UnicodeSyntax, RankNTypes #-}
+{-# LANGUAGE CPP, NoImplicitPrelude, UnicodeSyntax, RankNTypes, ImpredicativeTypes #-}
 
 #if __GLASGOW_HASKELL__ >= 701
 {-# LANGUAGE Trustworthy #-}
diff --git a/Control/Concurrent/Thread/Group.hs b/Control/Concurrent/Thread/Group.hs
--- a/Control/Concurrent/Thread/Group.hs
+++ b/Control/Concurrent/Thread/Group.hs
@@ -2,6 +2,7 @@
            , DeriveDataTypeable
            , NoImplicitPrelude
            , UnicodeSyntax
+           , ImpredicativeTypes
            , RankNTypes #-}
 
 #if __GLASGOW_HASKELL__ >= 701
diff --git a/threads.cabal b/threads.cabal
--- a/threads.cabal
+++ b/threads.cabal
@@ -1,5 +1,5 @@
 name:          threads
-version:       0.5.1.0
+version:       0.5.1.1
 cabal-version: >= 1.9.2
 build-type:    Custom
 stability:     experimental
@@ -45,7 +45,7 @@
 -------------------------------------------------------------------------------
 
 library
-  build-depends: base                 >= 4.4   && < 4.7
+  build-depends: base                 >= 4.4   && < 4.8
                , base-unicode-symbols >= 0.1.1 && < 0.3
                , stm                  >= 2.1   && < 2.5
   exposed-modules: Control.Concurrent.Thread
@@ -62,7 +62,7 @@
   ghc-options:    -Wall -threaded
 
   build-depends: threads
-               , base                 >= 4.4   && < 4.7
+               , base                 >= 4.4   && < 4.8
                , base-unicode-symbols >= 0.1.1 && < 0.3
                , stm                  >= 2.1   && < 2.5
                , concurrent-extra     >= 0.5.1 && < 0.8