diff -Nru php-sabre-http-4.2.1/debian/changelog php-sabre-http-4.2.1/debian/changelog
--- php-sabre-http-4.2.1/debian/changelog	2016-02-22 18:32:42.000000000 -0800
+++ php-sabre-http-4.2.1/debian/changelog	2016-03-15 08:50:46.000000000 -0700
@@ -1,3 +1,9 @@
+php-sabre-http (4.2.1-2ubuntu1) xenial; urgency=medium
+
+  * Add php-mbstring as a build & test dependency (LP: #1557599).
+
+ -- Nishanth Aravamudan <nish.aravamudan@canonical.com>  Tue, 15 Mar 2016 08:27:30 -0700
+
 php-sabre-http (4.2.1-2) unstable; urgency=medium
 
   * Upload to unstable now that php-sabre-http-3 provides the needed
diff -Nru php-sabre-http-4.2.1/debian/control php-sabre-http-4.2.1/debian/control
--- php-sabre-http-4.2.1/debian/control	2016-02-22 18:27:04.000000000 -0800
+++ php-sabre-http-4.2.1/debian/control	2016-03-15 08:48:35.000000000 -0700
@@ -1,13 +1,15 @@
 Source: php-sabre-http
 Section: php
 Priority: optional
-Maintainer: Debian PHP PEAR Maintainers <pkg-php-pear@lists.alioth.debian.org>
+Maintainer: Ubuntu Developers <ubuntu-devel-discuss@lists.ubuntu.com>
+XSBC-Original-Maintainer: Debian PHP PEAR Maintainers <pkg-php-pear@lists.alioth.debian.org>
 Uploaders: ownCloud for Debian maintainers <pkg-owncloud-maintainers@lists.alioth.debian.org>,
            David Prévot <taffit@debian.org>
 Build-Depends: debhelper (>= 9),
                php-cli,
                php-codesniffer,
                php-curl,
+               php-mbstring,
                php-sabre-event,
                php-sabre-uri,
                php-xdebug,
diff -Nru php-sabre-http-4.2.1/debian/tests/control php-sabre-http-4.2.1/debian/tests/control
--- php-sabre-http-4.2.1/debian/tests/control	2016-02-22 18:24:45.000000000 -0800
+++ php-sabre-http-4.2.1/debian/tests/control	2016-03-15 08:27:16.000000000 -0700
@@ -3,4 +3,4 @@
 
 Tests: phpunit
 Restrictions: rw-build-tree
-Depends: @, patch, php-curl, php-xdebug, phpunit
+Depends: @, patch, php-curl, php-msbstring, php-xdebug, phpunit