--- vorbis-tools-1.4.0-r1.ebuild
+++ vorbis-tools-1.4.0-r1.ebuild
@@ -30,6 +30,7 @@
 
 src_prepare() {
 	epatch "${FILESDIR}"/${P}-underlinking.patch
+	sed -e "s/AM_CONFIG_HEADER/AC_CONFIG_HEADERS/" -i configure.ac
 	eautoreconf
 }