diff -Nru php-apigen-4.1.2/debian/changelog php-apigen-4.1.2/debian/changelog
--- php-apigen-4.1.2/debian/changelog	2016-03-29 15:38:35.000000000 -0700
+++ php-apigen-4.1.2/debian/changelog	2016-03-31 12:47:36.000000000 -0700
@@ -1,3 +1,9 @@
+php-apigen (4.1.2-1ubuntu3) xenial; urgency=medium
+
+  * Add runtime dependency on php-mbstring (LP: #1557599).
+
+ -- Nishanth Aravamudan <nish.aravamudan@canonical.com>  Thu, 31 Mar 2016 12:42:34 -0700
+
 php-apigen (4.1.2-1ubuntu2) xenial; urgency=medium
 
   * Correctly update regex (LP: #1563098). 
diff -Nru php-apigen-4.1.2/debian/control php-apigen-4.1.2/debian/control
--- php-apigen-4.1.2/debian/control	2016-03-28 15:15:29.000000000 -0700
+++ php-apigen-4.1.2/debian/control	2016-03-31 12:42:32.000000000 -0700
@@ -23,6 +23,7 @@
 Package: php-apigen
 Architecture: all
 Depends: php-fshl (>= 2.1.0-2~),
+         php-mbstring,
          php-tokenreflection (>= 1.4.0-2~),
          ${misc:Depends},
          ${phpcomposer:Debian-require}