diff --git a/conf/overleaf-history-v1.service b/conf/overleaf-history-v1.service
index 917dc41..d055da9 100644
--- a/conf/overleaf-history-v1.service
+++ b/conf/overleaf-history-v1.service
@@ -8,7 +8,6 @@ User=__APP__
 Group=__APP__
 WorkingDirectory=__INSTALL_DIR__/
 EnvironmentFile=__INSTALL_DIR__/variables.env
-Environment="MONGO_CONNECTION_STRING=mongodb://127.0.0.1:27017/__DB_NAME__"
 Environment="NODE_CONFIG_DIR=__INSTALL_DIR__/live/services/history-v1/config"
 ExecStart=__YNH_NODE__ __INSTALL_DIR__/live/services/history-v1/app.js
 StandardOutput=append:/var/log/__APP__/history-v1.log