diff --git a/src/entry.sh b/src/entry.sh
index 99c28b3..6b204af 100644
--- a/src/entry.sh
+++ b/src/entry.sh
@@ -1,11 +1,10 @@
 #!/usr/bin/env bash
 set -Eeuo pipefail
 
+: "${APP:="macOS"}"
 : "${VGA:="vmware"}"
 : "${DISK_TYPE:="blk"}"
-
-APP="macOS"
-SUPPORT="https://github.com/dockur/macos"
+: "${SUPPORT:="https://github.com/dockur/macos"}"
 
 cd /run