diff --git a/.env.sample b/.env.sample
index 5a201a6..60bd918 100644
--- a/.env.sample
+++ b/.env.sample
@@ -90,6 +90,7 @@ SINGLE_USER_MODE=false
 DEFAULT_LOCALE=en
 # MAX_SESSION_ACTIVATIONS=
 # USER_ACTIVE_DAYS=
+# MAX_TOOT_CHARS=500
 
 # Sending mail
 # ============
diff --git a/compose.yml b/compose.yml
index 450649a..47e1c60 100644
--- a/compose.yml
+++ b/compose.yml
@@ -142,6 +142,7 @@ services:
       - VAPID_PRIVATE_KEY_FILE=/run/secrets/vapid_private_key
       - VAPID_PUBLIC_KEY
       - WEB_DOMAIN
+      - MAX_TOOT_CHARS
       - http_proxy # yes, this should be lowercase
 
   db: