diff -Nru ghostscript-9.18~dfsg~0/debian/changelog ghostscript-9.18~dfsg~0/debian/changelog
--- ghostscript-9.18~dfsg~0/debian/changelog	2016-02-29 10:36:07.000000000 +0000
+++ ghostscript-9.18~dfsg~0/debian/changelog	2016-04-23 14:52:04.000000000 +0000
@@ -1,3 +1,21 @@
+ghostscript (9.18~dfsg~0-0ubuntu5) yakkety; urgency=medium
+
+  * Mark png_push_fill_buffer symbol as optional.
+
+ -- Matthias Klose <doko@ubuntu.com>  Sat, 23 Apr 2016 16:51:29 +0200
+
+ghostscript (9.18~dfsg~0-0ubuntu4) yakkety; urgency=medium
+
+  * libgs-dev: Depend on libpng-dev.
+
+ -- Matthias Klose <doko@ubuntu.com>  Sat, 23 Apr 2016 16:12:35 +0200
+
+ghostscript (9.18~dfsg~0-0ubuntu3) yakkety; urgency=medium
+
+  * No-change rebuild for libpng soname change.
+
+ -- Matthias Klose <doko@ubuntu.com>  Sat, 23 Apr 2016 00:07:03 +0000
+
 ghostscript (9.18~dfsg~0-0ubuntu2) xenial; urgency=medium
 
   * Backport change from Debian 
diff -Nru ghostscript-9.18~dfsg~0/debian/control ghostscript-9.18~dfsg~0/debian/control
--- ghostscript-9.18~dfsg~0/debian/control	2016-01-27 22:19:20.000000000 +0000
+++ ghostscript-9.18~dfsg~0/debian/control	2016-04-23 14:12:33.000000000 +0000
@@ -140,7 +140,7 @@
  libjbig2dec0-dev,
  libjpeg-dev,
  libpaper-dev,
- libpng12-0-dev,
+ libpng-dev,
  libtiff5-dev,
  zlib1g-dev,
  ${cdbs:Depends},
diff -Nru ghostscript-9.18~dfsg~0/debian/control.in ghostscript-9.18~dfsg~0/debian/control.in
--- ghostscript-9.18~dfsg~0/debian/control.in	2016-02-29 10:38:55.000000000 +0000
+++ ghostscript-9.18~dfsg~0/debian/control.in	2016-04-23 14:52:06.000000000 +0000
@@ -133,7 +133,7 @@
  libjpeg-dev,
  liblcms2-dev,
  libpaper-dev,
- libpng12-0-dev,
+ libpng-dev,
  libtiff5-dev,
  zlib1g-dev,
  ${cdbs:Depends},
diff -Nru ghostscript-9.18~dfsg~0/debian/control.in.in ghostscript-9.18~dfsg~0/debian/control.in.in
--- ghostscript-9.18~dfsg~0/debian/control.in.in	2016-01-27 22:07:33.000000000 +0000
+++ ghostscript-9.18~dfsg~0/debian/control.in.in	2016-04-23 14:12:19.000000000 +0000
@@ -133,7 +133,7 @@
  libjpeg-dev,
  liblcms2-dev,
  libpaper-dev,
- libpng12-0-dev,
+ libpng-dev,
  libtiff5-dev,
  zlib1g-dev,
  ${cdbs:Depends},
diff -Nru ghostscript-9.18~dfsg~0/debian/symbols.common ghostscript-9.18~dfsg~0/debian/symbols.common
--- ghostscript-9.18~dfsg~0/debian/symbols.common	2016-02-13 00:10:02.000000000 +0000
+++ ghostscript-9.18~dfsg~0/debian/symbols.common	2016-04-23 14:51:27.000000000 +0000
@@ -4799,7 +4799,7 @@
  pixel_image_params@Base 8.61.dfsg.1
  pixmap_high_level_pattern@Base 9.08~rc1~dfsg-0ubuntu1
  plane_device_init@Base 8.61.dfsg.1
- png_push_fill_buffer@Base 8.61.dfsg.1
+ (optional)png_push_fill_buffer@Base 8.61.dfsg.1
  pop_estack@Base 8.61.dfsg.1
  pprintd1@Base 8.61.dfsg.1
  pprintd2@Base 8.61.dfsg.1