Index: kernel/generic/include/errno.h
===================================================================
--- kernel/generic/include/errno.h	(revision 645d9ed2a676dc71859db456dc0f1b504767fcea)
+++ kernel/generic/include/errno.h	(revision a1696d85772a5a21e574edb5264f91a5d3df7859)
@@ -57,4 +57,5 @@
 #define EBUSY           -14     /* Resource is busy */
 #define EOVERFLOW	-15	/* The result does not fit its size. */
+#define EINTR		-16	/* Operation was interrupted. */
 
 #endif
Index: kernel/generic/include/ipc/ipc.h
===================================================================
--- kernel/generic/include/ipc/ipc.h	(revision 645d9ed2a676dc71859db456dc0f1b504767fcea)
+++ kernel/generic/include/ipc/ipc.h	(revision a1696d85772a5a21e574edb5264f91a5d3df7859)
@@ -294,5 +294,5 @@
 extern void ipc_answer(answerbox_t *, call_t *);
 extern int ipc_call(phone_t *, call_t *);
-extern void ipc_call_sync(phone_t *, call_t *);
+extern int ipc_call_sync(phone_t *, call_t *);
 extern void ipc_phone_init(phone_t *);
 extern void ipc_phone_connect(phone_t *, answerbox_t *);