diff --git a/env.template b/env.template
index c9976e0..4547b51 100644
--- a/env.template
+++ b/env.template
@@ -46,6 +46,8 @@ LDAP_METHOD=plain
 SECRET_KEY_BASE=
 OTP_SECRET=
 
+UPDATE_CHECK_URL=
+
 # Optionally change default language
 # DEFAULT_LOCALE=de
 
diff --git a/start.sh b/start.sh
index 813a9e5..3bc3ddc 100755
--- a/start.sh
+++ b/start.sh
@@ -67,6 +67,10 @@ else
     HOME=/app/data SAFETY_ASSURED=1 bundle exec rails db:migrate
 fi
 
+if ! grep -q UPDATE_CHECK_URL /app/data/env.production; then
+    echo -e "\nUPDATE_CHECK_URL=" >> /app/data/env.production
+fi
+
 chown -R cloudron:cloudron /tmp/mastodon /run/mastodon
 
 if [[ "$(stat -c '%U' /app/data)" != "cloudron" ]]; then