diff --git a/alpine/Dockerfile b/alpine/Dockerfile
index 38ba941..afd24c5 100644
--- a/alpine/Dockerfile
+++ b/alpine/Dockerfile
@@ -5,6 +5,7 @@ ARG INSTALL_SCRIPT=https://raw.githubusercontent.com/fithwum/foundryvtt/master/a
 
 ENV PUID=99
 ENV GUID=100
+ENV GAME_PORT=30000
 
 RUN adduser -D -u 99 -G users -h /foundry -s /bin/bash foundry
 
diff --git a/debian/Dockerfile b/debian/Dockerfile
index 16c11d0..46f4344 100644
--- a/debian/Dockerfile
+++ b/debian/Dockerfile
@@ -5,6 +5,7 @@ ARG INSTALL_SCRIPT=https://raw.githubusercontent.com/fithwum/foundryvtt/master/d
 
 ENV PUID=99
 ENV GUID=100
+ENV GAME_PORT=30000
 
 RUN addgroup foundry && adduser -q --disabled-password --ingroup foundry foundry