--- m4/gecko.m4.orig	2008-08-27 21:38:50.000000000 -0400
+++ m4/gecko.m4	2008-08-27 21:43:26.000000000 -0400
@@ -63,10 +63,10 @@
 _geckos="libxul firefox mozilla-firefox seamonkey mozilla libxul-embedding xulrunner "
 if test -z "$gecko_cv_gecko"; then
 	for lizard in $_geckos; do
-		if $PKG_CONFIG --exists $lizard-xpcom; then
+		if test x`$PKG_CONFIG --modversion $lizard-xpcom 2>/dev/null | cut -d. -f1,2` = "x1.8"; then
 			gecko_cv_gecko=$lizard
 			break;
-		elif $PKG_CONFIG --exists $lizard; then
+		elif test x`$PKG_CONFIG --modversion $lizard 2>/dev/null | cut -d. -f1,2` = "x1.8"; then
 			gecko_cv_gecko=$lizard
 			break;
 		fi