$OpenBSD: patch-config_configure_in,v 1.11 2009/10/29 08:28:10 giovanni Exp $
--- config/configure.in.orig	Tue Oct 27 05:39:25 2009
+++ config/configure.in	Tue Oct 27 05:41:56 2009
@@ -845,7 +845,7 @@ if test "$GD" != "no"; then
       PNG_LDFLAGS=`$PNGLIBCONFIG --ldflags`
       LDFLAGS="$LDFLAGS $PNG_LDFLAGS"
     fi
-    AC_CHECK_LIB(png, png_create_read_struct , [LIBPNG=yes])
+    AC_CHECK_LIB(png, png_create_read_struct , [LIBPNG=yes],, -lz -lm)
 # restore variables
     LIBS=$SAVE_LIBS_PNG
     CFLAGS=$SAVE_CFLAGS_PNG
@@ -873,7 +873,7 @@ if test "$GD" != "no"; then
         GD=yes
 	GD_PNG=yes
         AC_MSG_RESULT(yes)
-	AC_CHECK_LIB(png, png_access_version_number,[AC_DEFINE(HAVE_PNGVERSION, 1,)])
+	AC_CHECK_LIB(png, png_access_version_number,[AC_DEFINE(HAVE_PNGVERSION, 1,)],, -lz -lm)
         AC_DEFINE(HAVE_GD_PNG, 1, [Define to 1 if you have png support in libgd.])
       else
         AC_MSG_RESULT(no)