Index: libcfa/src/concurrency/kernel.cfa
===================================================================
--- libcfa/src/concurrency/kernel.cfa	(revision adaee12c0ffb9e51f4a887585418aea8df5d1aee)
+++ libcfa/src/concurrency/kernel.cfa	(revision 99b2407c52d53a1bc8b16e5d3269a34ff9ad94b9)
@@ -895,5 +895,7 @@
 		unsigned tail = *ctx->cq.tail;
 		if(head == tail) return false;
+		ready_schedule_lock();
 		ret = __cfa_io_drain( proc );
+		ready_schedule_unlock();
 	#endif
 	return ret;