diff -up stunnel-5.50/tools/stunnel.service.in.systemd-service stunnel-5.50/tools/stunnel.service.in
--- stunnel-5.50/tools/stunnel.service.in.systemd-service	2019-01-14 12:17:15.826868965 +0100
+++ stunnel-5.50/tools/stunnel.service.in	2019-01-14 12:18:21.186753131 +0100
@@ -5,6 +5,7 @@ After=syslog.target network.target
 [Service]
 ExecStart=@bindir@/stunnel
 Type=forking
+PrivateTmp=true
 
 [Install]
 WantedBy=multi-user.target