diff --git a/scripts/combined-image.sh b/scripts/combined-image.sh
index eecd3d7f20d7f225ada6be88725965c5453764df..30373e7566d20120b37a9b14845ee91a3b90271d 100644
--- a/scripts/combined-image.sh
+++ b/scripts/combined-image.sh
@@ -8,8 +8,8 @@ BLKSZ=65536
 }
 
 # Make sure provided images are 64k aligned.
-kern=$(tempfile)
-root=$(tempfile)
+kern=$(mktemp)
+root=$(mktemp)
 dd if="$1" of="$kern" bs=$BLKSZ conv=sync 2>/dev/null
 dd if="$2" of="$root" bs=$BLKSZ conv=sync 2>/dev/null