diff --git a/release/powerpc/mkisoimages.sh b/release/powerpc/mkisoimages.sh
index 63619fb6271..5d5e7500588 100644
--- a/release/powerpc/mkisoimages.sh
+++ b/release/powerpc/mkisoimages.sh
@@ -43,6 +43,8 @@ if [ "x$1" = "x-b" ]; then
 <boot-script>boot &device;:&partition;,\ppc\chrp\loader</boot-script>
 </chrp-boot>
 EOF
+	bootable="$bootable -o chrp-boot"
+
 	shift
 else
 	bootable=""