diff --git a/src/backends/meta-idle-monitor.c b/src/backends/meta-idle-monitor.c
index de1c7e0ba..e5124abc1 100644
--- a/src/backends/meta-idle-monitor.c
+++ b/src/backends/meta-idle-monitor.c
@@ -511,7 +511,7 @@ meta_idle_monitor_reset_idletime (MetaIdleMonitor *monitor)
 
       if (watch->timeout_msec == 0)
         {
-          meta_idle_monitor_watch_fire ((MetaIdleMonitorWatch *) watch);
+          meta_idle_monitor_watch_fire (watch);
         }
       else
         {