diff --git a/lib/Haskell/Prim/Functor.agda b/lib/Haskell/Prim/Functor.agda
index 489d9c50..96c065de 100644
--- a/lib/Haskell/Prim/Functor.agda
+++ b/lib/Haskell/Prim/Functor.agda
@@ -75,4 +75,4 @@ instance
   iFunctorTuple₃ : Functor (a × b ×_)
   iFunctorTuple₃ = fmap= λ where f (x , y , z) → x , y , f z
 
-instance postulate iFunctiorIO : Functor IO
+instance postulate iFunctorIO : Functor IO