diff --git a/bytestring-tree-builder.cabal b/bytestring-tree-builder.cabal
--- a/bytestring-tree-builder.cabal
+++ b/bytestring-tree-builder.cabal
@@ -1,7 +1,7 @@
 name:
   bytestring-tree-builder
 version:
-  0.2.2
+  0.2.2.1
 category:
   ByteString
 synopsis:
diff --git a/library/ByteString/TreeBuilder.hs b/library/ByteString/TreeBuilder.hs
--- a/library/ByteString/TreeBuilder.hs
+++ b/library/ByteString/TreeBuilder.hs
@@ -11,7 +11,7 @@
 )
 where
 
-import ByteString.TreeBuilder.Prelude hiding (foldl, length)
+import ByteString.TreeBuilder.Prelude hiding (foldl, foldr, length)
 import qualified ByteString.TreeBuilder.Tree as A
 import qualified ByteString.TreeBuilder.Poker as D
 import qualified ByteString.TreeBuilder.Prelude as F
@@ -69,6 +69,13 @@
   A.foldl step init tree
 
 -- |
+-- Performs a right-fold over the aggregated chunks.
+{-# INLINE foldr #-}
+foldr :: (ByteString -> a -> a) -> a -> Builder -> a
+foldr step init (Builder length tree) =
+  A.foldr step init tree
+
+-- |
 -- /O(1)/. Gets the total length.
 {-# INLINE length #-}
 length :: Builder -> Int
@@ -88,4 +95,4 @@
 {-# INLINABLE toLazyByteString #-}
 toLazyByteString :: Builder -> E.ByteString
 toLazyByteString =
-  foldl (flip E.Chunk) E.Empty
+  foldr E.Chunk E.Empty
diff --git a/tasty/Main.hs b/tasty/Main.hs
--- a/tasty/Main.hs
+++ b/tasty/Main.hs
@@ -6,6 +6,7 @@
 import Test.Tasty.HUnit
 import Test.Tasty.QuickCheck
 import ByteString.TreeBuilder
+import qualified Data.ByteString.Lazy
 
 
 main =
@@ -14,8 +15,13 @@
 tree =
   testGroup "All tests"
   [
-    testProperty "Concatting a list of bytestrings is isomorphic to appending a list of builders" $
+    testProperty "Concatting a list of bytestrings is isomorphic to appending a list of builders (strict)" $
     \bytestrings ->
-      mconcat bytestrings ==
+      mconcat bytestrings ===
       toByteString (foldMap byteString bytestrings)
+    ,
+    testProperty "Concatting a list of bytestrings is isomorphic to appending a list of builders (lazy)" $
+    \bytestrings ->
+      mconcat bytestrings ===
+      Data.ByteString.Lazy.toStrict (toLazyByteString (foldMap byteString bytestrings))
   ]