diff --git a/changelog b/changelog
--- a/changelog
+++ b/changelog
@@ -1,3 +1,7 @@
+cmark 0.5.5.1 (20 Mar 2017)
+
+  * Update version bound for HUnit.
+
 cmark 0.5.5 (31 Jan 2017)
 
   * Update to cmark 0.27.1.
diff --git a/cmark.cabal b/cmark.cabal
--- a/cmark.cabal
+++ b/cmark.cabal
@@ -1,5 +1,5 @@
 name:                cmark
-version:             0.5.5
+version:             0.5.5.1
 synopsis:            Fast, accurate CommonMark (Markdown) parser and renderer
 description:
   This package provides Haskell bindings for
@@ -104,6 +104,6 @@
   type:           exitcode-stdio-1.0
   main-is:        test-cmark.hs
   hs-source-dirs: test
-  build-depends:  base, cmark, text, HUnit >= 1.2 && < 1.6
+  build-depends:  base, cmark, text, HUnit >= 1.2 && < 1.7
   ghc-options:    -Wall -fno-warn-unused-do-bind -threaded
   default-language: Haskell98