diff --git a/Graphics/Rendering/OpenGL/GL/IOState.hs b/Graphics/Rendering/OpenGL/GL/IOState.hs
index 6fbc144..2c2a42d 100644
--- a/Graphics/Rendering/OpenGL/GL/IOState.hs
+++ b/Graphics/Rendering/OpenGL/GL/IOState.hs
@@ -21 +21,2 @@ module Graphics.Rendering.OpenGL.GL.IOState (
-import Control.Monad(replicateM)
+import Control.Applicative
+import Control.Monad(replicateM,ap)
@@ -31,0 +33,4 @@ instance Functor (IOState s) where
+instance Applicative (IOState s) where
+    pure  = return
+    (<*>) = ap  -- defined in Control.Monad
+