diff -Nru ghostscript-9.18~dfsg~0/debian/changelog ghostscript-9.18~dfsg~0/debian/changelog
--- ghostscript-9.18~dfsg~0/debian/changelog	2016-04-23 14:12:59.000000000 +0000
+++ ghostscript-9.18~dfsg~0/debian/changelog	2016-04-23 14:52:04.000000000 +0000
@@ -1,3 +1,9 @@
+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.
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