--- libast-0.5-r2.ebuild.orig	2005-03-06 12:06:17.000000000 +0100
+++ libast-0.5-r2.ebuild	2005-03-08 15:25:32.000000000 +0100
@@ -25,9 +25,17 @@
 }
 
 src_compile() {
+	local mymmx=""
+
+	if use amd64; then
+		mymmx="--enable-mmx"
+	else
+		mymmx=`use_enable mmx`
+	fi
+
 	econf \
 		$(use_enable imlib) \
-		$(use_enable mmx) \
+		${mymmx} \
 		|| die
 	emake || die
 }