diff --git a/nixos/modules/services/mail/exim.nix b/nixos/modules/services/mail/exim.nix
index cd0da4fc5098..a9504acee351 100644
--- a/nixos/modules/services/mail/exim.nix
+++ b/nixos/modules/services/mail/exim.nix
@@ -116,8 +116,9 @@ in
       wantedBy = [ "multi-user.target" ];
       restartTriggers = [ config.environment.etc."exim.conf".source ];
       serviceConfig = {
-        ExecStart   = "${cfg.package}/bin/exim -bdf -q${cfg.queueRunnerInterval}";
-        ExecReload  = "${coreutils}/bin/kill -HUP $MAINPID";
+        ExecStart   = "+${cfg.package}/bin/exim -bdf -q${cfg.queueRunnerInterval}";
+        ExecReload  = "+${coreutils}/bin/kill -HUP $MAINPID";
+        User        = cfg.user;
       };
       preStart = ''
         if ! test -d ${cfg.spoolDir}; then