diff --git a/.env.example b/.env.example
index a176e0d..acb1a63 100644
--- a/.env.example
+++ b/.env.example
@@ -9,3 +9,4 @@ HLEDGER_PASSWORD_HASH=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
 
 FLATNOTES_USERNAME=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
 FLATNOTES_PASSWORD=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
+FLATNOTES_SECRET_KEY=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
diff --git a/compose.yml b/compose.yml
index 1aaeba0..39331ad 100644
--- a/compose.yml
+++ b/compose.yml
@@ -111,6 +111,7 @@ services:
       - TZ=Europe/Zurich
       - FLATNOTES_USERNAME=${FLATNOTES_USERNAME}
       - FLATNOTES_PASSWORD=${FLATNOTES_PASSWORD}
+      - FLATNOTES_SECRET_KEY=${FLATNOTES_SECRET_KEY}
 
     volumes:
       # Flatnotes config / app data