diff --git a/roles/zeitbild_backend/templates/conf.json.j2 b/roles/zeitbild_backend/templates/conf.json.j2
index 53a99b9..7653e1a 100644
--- a/roles/zeitbild_backend/templates/conf.json.j2
+++ b/roles/zeitbild_backend/templates/conf.json.j2
@@ -54,7 +54,7 @@
 {% endif %}
 	"session_management": {
 		"in_memory": false,
-		"lifetime": 3600,
+		"lifetime": {{var_zeitbild_backend_session_lifetime | string}},
 		"drop_all_at_start": false
 	},
 	"caldav": {{var_zeitbild_backend_caldav | to_json}}
diff --git a/roles/zeitbild_backend/vardef.json b/roles/zeitbild_backend/vardef.json
index db7ab95..979ffe2 100644
--- a/roles/zeitbild_backend/vardef.json
+++ b/roles/zeitbild_backend/vardef.json
@@ -88,5 +88,9 @@
 	"authentication_data_authelia_label": {
 		"type": "string",
 		"mandatory": false
+	},
+	"session_lifetime": {
+		"type": "integer",
+		"mandatory": false
 	}
 }