diff --git a/src/Data/NonEmpty.purs b/src/Data/NonEmpty.purs
index 957b88c..9e5f75a 100644
--- a/src/Data/NonEmpty.purs
+++ b/src/Data/NonEmpty.purs
@@ -20,7 +20,7 @@ import Data.Eq (class Eq1)
 import Data.Foldable (class Foldable, foldl, foldr, foldMap)
 import Data.FoldableWithIndex (class FoldableWithIndex, foldMapWithIndex, foldlWithIndex, foldrWithIndex)
 import Data.FunctorWithIndex (class FunctorWithIndex, mapWithIndex)
-import Data.Maybe (Maybe(..))
+import Data.Maybe (Maybe(..), maybe)
 import Data.Ord (class Ord1)
 import Data.Semigroup.Foldable (class Foldable1, foldMap1)
 import Data.Traversable (class Traversable, traverse, sequence)
@@ -107,6 +107,8 @@ instance traversableWithIndexNonEmpty
 instance foldable1NonEmpty :: Foldable f => Foldable1 (NonEmpty f) where
   fold1 = foldMap1 identity
   foldMap1 f (a :| fa) = foldl (\s a1 -> s <> f a1) (f a) fa
+  foldr1 f (a :| fa) = maybe a (f a) $ foldr (\a1 -> Just <<< maybe a1 (f a1)) Nothing fa
+  foldl1 = foldl1
 
 instance unfoldable1NonEmpty :: Unfoldable f => Unfoldable1 (NonEmpty f) where
   unfoldr1 f b = uncurry (:|) $ unfoldr (map f) <$> f b
diff --git a/test/Main.purs b/test/Main.purs
index b0a7e9a..9e3fcac 100644
--- a/test/Main.purs
+++ b/test/Main.purs
@@ -5,7 +5,7 @@ import Prelude
 import Data.Foldable (fold, foldl)
 import Data.Maybe (Maybe(..))
 import Data.NonEmpty (NonEmpty, (:|), foldl1, oneOf, head, tail, singleton)
-import Data.Semigroup.Foldable (fold1)
+import Data.Semigroup.Foldable (fold1, foldr1)
 import Data.Unfoldable1 as U1
 import Effect (Effect)
 import Test.Assert (assert)
@@ -19,7 +19,8 @@ main :: Effect Unit
 main = do
   assert $ singleton 0 == 0 :| []
   assert $ 0 :| Nothing /= 0 :| Just 1
-  assert $ foldl1 (+) (1 :| [2, 3]) == 6
+  assert $ foldl1 (\l r -> "(" <> l <> r <> ")") ("a" :| ["b", "c", "d"]) == "(((ab)c)d)"
+  assert $ foldr1 (\l r -> "(" <> l <> r <> ")") ("a" :| ["b", "c", "d"]) == "(a(b(cd)))"
   assert $ foldl (+) 0 (1 :| [2, 3]) == 6
   assert $ fold1 ("Hello" :| [" ", "World"]) == "Hello World"
   assert $ fold ("Hello" :| [" ", "World"]) == "Hello World"