diff --git a/compose.shared-host.yaml b/compose.shared-host.yaml
index b9bf34a..9f08a34 100644
--- a/compose.shared-host.yaml
+++ b/compose.shared-host.yaml
@@ -18,8 +18,10 @@ services:
     build: .
     restart: unless-stopped
     environment:
-      GS_DB_PATH: /data/ghoststandard.sqlite
-      GS_PORT:    "8080"
+      GS_DB_PATH:  /data/ghoststandard.sqlite
+      GS_PORT:     "8080"
+      # Read by the setup wizard to pre-fill the bridge URL prompt. Optional.
+      GS_HOSTNAME: ${GS_HOSTNAME:-}
     volumes:
       - gs_data:/data
       - ./assets:/data/assets:ro
diff --git a/compose.yaml b/compose.yaml
index 0f2a18a..23a4c2d 100644
--- a/compose.yaml
+++ b/compose.yaml
@@ -13,8 +13,10 @@ services:
     build: .
     restart: unless-stopped
     environment:
-      GS_DB_PATH: /data/ghoststandard.sqlite
-      GS_PORT:    "8080"
+      GS_DB_PATH:  /data/ghoststandard.sqlite
+      GS_PORT:     "8080"
+      # Read by the setup wizard to pre-fill the bridge URL prompt. Optional.
+      GS_HOSTNAME: ${GS_HOSTNAME:-}
     volumes:
       - gs_data:/data
       # Drop your 512×512 publication icon (and anything else you want the CLI