--- a/src/Linear/Instances.hs
+++ b/src/Linear/Instances.hs
@@ -21,8 +21,10 @@ import Control.Monad.Zip
 import Data.Complex
 import Data.Orphans ()
 
+#if ! MIN_VERSION_base_orphans(0,8,3)
 instance MonadZip Complex where
   mzipWith = liftA2
 
 instance MonadFix Complex where
   mfix f = (let a :+ _ = f a in a) :+ (let _ :+ a = f a in a)
+#endif