diff --git a/bus/system.conf.in b/bus/system.conf.in
index 92f4cc42..851b9e63 100644
--- a/bus/system.conf.in
+++ b/bus/system.conf.in
@@ -68,6 +68,14 @@
     <deny send_destination="org.freedesktop.DBus"
           send_interface="org.freedesktop.DBus"
           send_member="UpdateActivationEnvironment"/>
+    <deny send_destination="org.freedesktop.DBus"
+          send_interface="org.freedesktop.systemd1.Activator"/>
+  </policy>
+
+  <!-- Only systemd, which runs as root, may report activation failures. -->
+  <policy user="root">
+    <allow send_destination="org.freedesktop.DBus"
+           send_interface="org.freedesktop.systemd1.Activator"/>
   </policy>
 
   <!-- Config files are placed here that among other things, punch