--- a/gloss.cabal
+++ b/gloss.cabal
@@ -37,8 +37,8 @@
 
 Library
   Build-Depends: 
-        base       == 4.8.*,
-        ghc-prim   == 0.4.*,
+        base,
+        ghc-prim,
         containers == 0.5.*,
         bytestring == 0.10.*,
         OpenGL     >= 2.12 && < 3.1,
--- a/Graphics/Gloss/Internals/Interface/Event.hs
+++ b/Graphics/Gloss/Internals/Interface/Event.hs
@@ -6,6 +6,7 @@
 where
 import Data.IORef
 import Graphics.Gloss.Internals.Interface.Backend
+import Data.Functor
 
 -- | Possible input events.
 data Event
--- a/Graphics/Gloss/Internals/Interface/Display.hs
+++ b/Graphics/Gloss/Internals/Interface/Display.hs
@@ -17,6 +17,7 @@
 import qualified Graphics.Gloss.Internals.Interface.Callback as Callback
 import Data.IORef
 import System.Mem
+import Data.Functor
 
 
 displayWithBackend
--- a/Graphics/Gloss/Internals/Interface/Animate.hs
+++ b/Graphics/Gloss/Internals/Interface/Animate.hs
@@ -21,7 +21,7 @@
 import Control.Monad
 import System.Mem
 import GHC.Float (double2Float)
-
+import Data.Functor
 
 animateWithBackendIO
         :: Backend a
--- a/Graphics/Gloss/Internals/Interface/Simulate.hs
+++ b/Graphics/Gloss/Internals/Interface/Simulate.hs
@@ -22,6 +22,7 @@
 import qualified Graphics.Gloss.Internals.Interface.Animate.State       as AN
 import Data.IORef
 import System.Mem
+import Data.Functor
 
 
 simulateWithBackendIO
