diff --git a/fly.toml b/fly.toml
index 0fb7b35..64765e5 100644
--- a/fly.toml
+++ b/fly.toml
@@ -3,10 +3,12 @@ primary_region = "lax"
 
 [build]
   dockerfile = "Dockerfile"
+  [build.args]
+    GITEA_APP_NAME = "git-pr"
 
 [env]
-  GITEA__server__DOMAIN = "git-pr.fly.dev"
-  GITEA__server__ROOT_URL = "https://git-pr.fly.dev/"
+  GITEA__server__DOMAIN = "${GITEA_APP_NAME}.fly.dev"
+  GITEA__server__ROOT_URL = "https://${GITEA_APP_NAME}.fly.dev/"
 
 [[mounts]]
   source = "gitea_data"