diff --git a/Makefile b/Makefile
index a4897c4..9ab13e1 100644
--- a/Makefile
+++ b/Makefile
@@ -206,7 +206,7 @@ ${bld}/os.iso: ${bld}/iso_files/os.zip ${bld}/iso_files/boot/iso_boot.sys ${bld}
 	! test -d ${bld}/iso_files.tmp
 	cp -a -T -- ${bld}/iso_files ${bld}/iso_files.tmp
 	find ${bld}/iso_files.tmp -depth -exec touch -t ${commit_timestamp} '{}' ';'
-	faketime -f ${commit_faketime} mkisofs \
+	(cd ./${bld}/iso_files.tmp/ && faketime -f ${commit_faketime} mkisofs \
 	 --input-charset utf-8 \
 	 -rock \
 	 -joliet \
@@ -215,8 +215,8 @@ ${bld}/os.iso: ${bld}/iso_files/os.zip ${bld}/iso_files/boot/iso_boot.sys ${bld}
 	 -no-emul-boot \
 	 -boot-load-size 4 \
 	 -pad \
-	 -output $@ \
-	 ./${bld}/iso_files.tmp/
+	 -output ../os.iso \
+	 .)
 	rm -- ${bld}/iso_files.tmp/os.zip \
               ${bld}/iso_files.tmp/boot/iso_boot.sys
 	rmdir ${bld}/iso_files.tmp/boot/