Index: kernel/generic/include/ipc/sysipc.h
===================================================================
--- kernel/generic/include/ipc/sysipc.h	(revision 6c4a56f3dfeb76e8cadec584d06e5862d6074d3e)
+++ kernel/generic/include/ipc/sysipc.h	(revision 8619f25f028ddffad4600e71ac3a6f36b95ebd7c)
@@ -52,4 +52,5 @@
 unative_t sys_ipc_wait_for_call(ipc_data_t *calldata, uint32_t usec,
     int nonblocking);
+unative_t sys_ipc_poke(void);
 unative_t sys_ipc_forward_fast(unative_t callid, unative_t phoneid,
     unative_t method, unative_t arg1, unative_t arg2, int mode);
Index: kernel/generic/include/syscall/syscall.h
===================================================================
--- kernel/generic/include/syscall/syscall.h	(revision 6c4a56f3dfeb76e8cadec584d06e5862d6074d3e)
+++ kernel/generic/include/syscall/syscall.h	(revision 8619f25f028ddffad4600e71ac3a6f36b95ebd7c)
@@ -66,4 +66,5 @@
 	SYS_IPC_FORWARD_SLOW,
 	SYS_IPC_WAIT,
+	SYS_IPC_POKE,
 	SYS_IPC_HANGUP,
 	SYS_IPC_REGISTER_IRQ,
Index: kernel/generic/src/ipc/sysipc.c
===================================================================
--- kernel/generic/src/ipc/sysipc.c	(revision 6c4a56f3dfeb76e8cadec584d06e5862d6074d3e)
+++ kernel/generic/src/ipc/sysipc.c	(revision 8619f25f028ddffad4600e71ac3a6f36b95ebd7c)
@@ -44,4 +44,5 @@
 #include <ipc/ipcrsc.h>
 #include <ipc/kbox.h>
+#include <synch/waitq.h>
 #include <udebug/udebug_ipc.h>
 #include <arch/interrupt.h>
@@ -1051,4 +1052,11 @@
 }
 
+/** Interrupt one thread from sys_ipc_wait_for_call(). */
+unative_t sys_ipc_poke(void)
+{
+	waitq_unsleep(&TASK->answerbox.wq);	
+	return EOK;
+}
+
 /** Connect an IRQ handler to a task.
  *
Index: kernel/generic/src/syscall/syscall.c
===================================================================
--- kernel/generic/src/syscall/syscall.c	(revision 6c4a56f3dfeb76e8cadec584d06e5862d6074d3e)
+++ kernel/generic/src/syscall/syscall.c	(revision 8619f25f028ddffad4600e71ac3a6f36b95ebd7c)
@@ -137,4 +137,5 @@
 	(syshandler_t) sys_ipc_forward_slow,
 	(syshandler_t) sys_ipc_wait_for_call,
+	(syshandler_t) sys_ipc_poke,
 	(syshandler_t) sys_ipc_hangup,
 	(syshandler_t) sys_ipc_register_irq,