diff --git a/org.freedesktop.ModemManager.conf.nopolkit b/org.freedesktop.ModemManager.conf.nopolkit
index 6586652..512f878 100644
--- a/org.freedesktop.ModemManager.conf.nopolkit
+++ b/org.freedesktop.ModemManager.conf.nopolkit
@@ -88,6 +88,10 @@
     <allow send_destination="org.freedesktop.ModemManager"
            send_interface="org.freedesktop.ModemManager"
            send_member="EnumerateDevices"/>
+    <!-- Needed for debugd's SetDebugMode -->
+    <allow send_destination="org.freedesktop.ModemManager"
+           send_interface="org.freedesktop.ModemManager"
+           send_member="SetLogging"/>
     <allow send_destination="org.freedesktop.ModemManager"
            send_interface="org.freedesktop.ModemManager.Modem.Simple"
            send_member="GetStatus"/>