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:
-  0.2.1.4
+  0.2.2
 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
@@ -5,6 +5,7 @@
   byteString,
   byte,
   -- * Execution
+  length,
   toByteString,
   toLazyByteString,
 )