diff --git a/zlibs/iso b/zlibs/iso
index 1871c09..b5440e0 100644
--- a/zlibs/iso
+++ b/zlibs/iso
@@ -88,10 +88,13 @@ iso_squash_strap() {
 
 	notice "creating squashfs out of strapdir"
 
+	[[ -n "$mkefi" ]] && uefi_opt="-Xbcj x86"
 	pushd $workdir
 	sudo mksquashfs $strapdir binary/live/filesystem.squashfs \
+		${=uefi_opt} \
 		-noappend -comp xz || zerr
 	popd
+	unset uefi_opt
 }
 
 iso_xorriso_build() {
@@ -121,6 +124,7 @@ iso_xorriso_build() {
 		-o $R/dist/$isoname \
 		binary || zerr
 	popd
+	unset uefi_opt
 }
 
 iso_setup_installer() {