diff --git a/Formula/libunistring.rb b/Formula/libunistring.rb
index c78e84103d8a0..c72be9901b56d 100644
--- a/Formula/libunistring.rb
+++ b/Formula/libunistring.rb
@@ -1,9 +1,9 @@
 class Libunistring < Formula
   desc "C string library for manipulating Unicode strings"
   homepage "https://www.gnu.org/software/libunistring/"
-  url "https://ftp.gnu.org/gnu/libunistring/libunistring-0.9.8.tar.xz"
-  mirror "https://ftpmirror.gnu.org/libunistring/libunistring-0.9.8.tar.xz"
-  sha256 "7b9338cf52706facb2e18587dceda2fbc4a2a3519efa1e15a3f2a68193942f80"
+  url "https://ftp.gnu.org/gnu/libunistring/libunistring-0.9.9.tar.xz"
+  mirror "https://ftpmirror.gnu.org/libunistring/libunistring-0.9.9.tar.xz"
+  sha256 "a4d993ecfce16cf503ff7579f5da64619cee66226fb3b998dafb706190d9a833"
 
   bottle do
     cellar :any