diff --git a/one-container/docker-compose.yaml b/one-container/docker-compose.yaml
index 82a05cb..8bd087e 100644
--- a/one-container/docker-compose.yaml
+++ b/one-container/docker-compose.yaml
@@ -14,15 +14,15 @@ services:
       - 443:443/tcp
       - 53:53/tcp
       - 53:53/udp
-      - ${PIHOLE_WEBPORT}:80/tcp #Allows use of different port to access pihole web interface when other docker containers use port 80
+      - ${PIHOLE_WEBPORT:-80}:80/tcp #Allows use of different port to access pihole web interface when other docker containers use port 80
       # - 5335:5335/tcp # Uncomment to enable unbound access on local server
       # - 22/tcp # Uncomment to enable SSH
     environment:
       - FTLCONF_REPLY_ADDR4=${FTLCONF_REPLY_ADDR4}
-      - TZ=${TZ}
+      - TZ=${TZ:-UTC}
       - WEBPASSWORD=${WEBPASSWORD}
-      - WEBTHEME=${WEBTHEME}
-      - REV_SERVER=${REV_SERVER}
+      - WEBTHEME=${WEBTHEME:-default-light}
+      - REV_SERVER=${REV_SERVER:-false}
       - REV_SERVER_TARGET=${REV_SERVER_TARGET}
       - REV_SERVER_DOMAIN=${REV_SERVER_DOMAIN}
       - REV_SERVER_CIDR=${REV_SERVER_CIDR}