diff -urNad passage.orig/passage-4+dfsg1/debian/rules passage/passage-4+dfsg1/debian/rules
--- passage.orig/passage-4+dfsg1/debian/rules	2015-02-24 18:16:51.850025527 +0000
+++ passage/passage-4+dfsg1/debian/rules	2015-02-24 18:26:33.471606301 +0000
@@ -17,6 +17,7 @@
 	composite -compose CopyOpacity mask.png gamma256/build/macOSX/iconColor.png passage.png
 	convert -scale 32x32 passage.png 32x32/passage.png 
 	convert 32x32/passage.png 32x32/passage.xpm
+	set -e; for X in . 256x256 64x64 32x32; do convert $$X/passage.png +set date:create +set date:modify -define png:exclude-chunk=time $$X/passage.png; done
 	sed -i -e 's/PLATFORM_COMPILE_FLAGS = */PLATFORM_COMPILE_FLAGS = $$(CFLAGS) $$(CPPFLAGS) /' gamma256/gameSource/Makefile
 	sed -i -e 's/PLATFORM_LINK_FLAGS = */PLATFORM_LINK_FLAGS = $$(LDFLAGS) /' gamma256/gameSource/Makefile
 	$(MAKE) -C gamma256/gameSource LDFLAGS="$(LDFLAGS)" CPPFLAGS="$(CPPFLAGS)" CFLAGS="$(CFLAGS) -DETCDIR=\\\"/etc/passage\\\" -DDATADIR=\\\"/usr/share/games/passage/\\\""