diff --git a/src/Data/Lazy.purs b/src/Data/Lazy.purs
index 2fa336b..091c04c 100644
--- a/src/Data/Lazy.purs
+++ b/src/Data/Lazy.purs
@@ -102,6 +102,8 @@ instance foldableWithIndexLazy :: FoldableWithIndex Unit Lazy where
 instance foldable1Lazy :: Foldable1 Lazy where
   foldMap1 f l = f (force l)
   fold1 = fold1Default
+  foldr1 _ l = force l
+  foldl1 _ l = force l
 
 instance traversableLazy :: Traversable Lazy where
   traverse f l = defer <<< const <$> f (force l)