diff -Paur --no-dereference -- libpng.upstream/config.sub libpng/config.sub
--- libpng.upstream/config.sub
+++ libpng/config.sub
@@ -1337,7 +1337,7 @@
 	      | -hpux* | -unos* | -osf* | -luna* | -dgux* | -auroraux* | -solaris* \
 	      | -sym* | -kopensolaris* \
 	      | -amigaos* | -amigados* | -msdos* | -newsos* | -unicos* | -aof* \
-	      | -aos* | -aros* \
+	      | -aos* | -aros* | -sortix* \
 	      | -nindy* | -vxsim* | -vxworks* | -ebmon* | -hms* | -mvs* \
 	      | -clix* | -riscos* | -uniplus* | -iris* | -rtu* | -xenix* \
 	      | -hiux* | -386bsd* | -knetbsd* | -mirbsd* | -netbsd* \
diff -Paur --no-dereference -- libpng.upstream/libpng.pc.in libpng/libpng.pc.in
--- libpng.upstream/libpng.pc.in
+++ libpng/libpng.pc.in
@@ -6,6 +6,6 @@
 Name: libpng
 Description: Loads and saves PNG files
 Version: @PNGLIB_VERSION@
-Libs: -L${libdir} -lpng@PNGLIB_MAJOR@@PNGLIB_MINOR@
+Libs: -L${libdir} -lpng@PNGLIB_MAJOR@@PNGLIB_MINOR@ -lz -lm
 Libs.private: @LIBS@
 Cflags: -I${includedir}
diff -Paur --no-dereference -- libpng.upstream/Makefile.in libpng/Makefile.in
--- libpng.upstream/Makefile.in
+++ libpng/Makefile.in
@@ -1428,8 +1428,6 @@
 
 # do evil things to libpng to cause libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@ to be used
 install-exec-hook:
-	cd $(DESTDIR)$(bindir); rm -f libpng-config
-	cd $(DESTDIR)$(bindir); $(LN_S) $(PNGLIB_BASENAME)-config libpng-config
 	@set -x;\
 	cd $(DESTDIR)$(libdir);\
 	for ext in a la so so.@PNGLIB_MAJOR@@PNGLIB_MINOR@.@PNGLIB_RELEASE@ sl dylib dll.a; do\