diff --git a/build/pkg.build b/build/pkg.build
index 97b7adb..5c31f77 100644
--- a/build/pkg.build
+++ b/build/pkg.build
@@ -84,7 +84,7 @@ if [ -e ${PKG_SUBDIR}/configure -o							\
 		-exec install -m 0700 ${MIDIPIX_BUILD_PWD}/etc/config.sub {} \;;
 	if [ -e ${PKG_SUBDIR}/configure.ac -a						\
 	   ! -e ${PKG_SUBDIR}/configure ]; then
-		if [ -x ${PKG_SUBDIR}/autogen.sh ]; then
+		if [ -e ${PKG_SUBDIR}/autogen.sh ]; then
 			for __ in ${PKG_SUBDIR}/build-aux ${PKG_SUBDIR}; do
 				if [ -e ${__} ]; then
 					echo install -m 0700				\
@@ -96,7 +96,7 @@ if [ -e ${PKG_SUBDIR}/configure -o							\
 					break;
 				fi;
 			done;
-			(cd ${PKG_SUBDIR} && ./autogen.sh) || exit 1;
+			(cd ${PKG_SUBDIR} && ${SHELL} ./autogen.sh) || exit 1;
 		else
 			(cd ${PKG_SUBDIR} && autoconf) || exit 1;
 		fi;