--- dovecot.service.in
+++ dovecot.service.in
@@ -22,7 +22,8 @@ ExecReload=@bindir@/doveadm reload
 ExecStop=@bindir@/doveadm stop
 PrivateTmp=true
 NonBlocking=yes
-ProtectSystem=full
+# ProtectSystem requires systemd ≥ 214 (Fedora 22 onwards)
+#ProtectSystem=full
 ProtectHome=no
 
 # You can add environment variables with e.g.:
