diff --git a/docker-startup.sh b/docker-startup.sh
index eddb82ee27679c5307d9822f78311a8526fc1dea..7d7edb297719bef90de77a3c007a6457c04d55dd 100755
--- a/docker-startup.sh
+++ b/docker-startup.sh
@@ -1,6 +1,6 @@
 #!/bin/bash
 
-HTTP_PORT=${HTTP_PORT:8000}
+HTTP_PORT=${HTTP_PORT:-8000}
 
 if [[ -z $ALEKSIS_secret_key ]]; then
     if [[ ! -e /var/lib/aleksis/secret_key ]]; then