--- /dev/null
+--- a/lib/master.cc
++++ b/lib/master.cc
+@@ -409,7 +409,9 @@ Master::process_pending(RouterThread *th
+ while (Task *t = Task::pending_to_task(my_pending)) {
+ my_pending = t->_pending_nextptr;
+ t->_pending_nextptr = 0;
++# if HAVE_MULTITHREAD
+ click_master_mb();
++# endif
+ t->process_pending(thread);
+ }
+ }