Index: kernel/generic/include/ipc/sysipc.h
===================================================================
--- kernel/generic/include/ipc/sysipc.h	(revision bc50fc42c6550ecdf5e89f83b811c2db9ff38684)
+++ kernel/generic/include/ipc/sysipc.h	(revision 32099239a6124d59220f89570e99659141d22ed7)
@@ -45,6 +45,6 @@
     ipc_data_t *reply);
 unative_t sys_ipc_call_async_fast(unative_t phoneid, unative_t method, 
-    unative_t arg1, unative_t arg2);
-unative_t sys_ipc_call_async(unative_t phoneid, ipc_data_t *data);
+    unative_t arg1, unative_t arg2, unative_t arg3, unative_t arg4);
+unative_t sys_ipc_call_async_slow(unative_t phoneid, ipc_data_t *data);
 unative_t sys_ipc_answer_fast(unative_t callid, unative_t retval, 
     unative_t arg1, unative_t arg2);
Index: kernel/generic/include/syscall/syscall.h
===================================================================
--- kernel/generic/include/syscall/syscall.h	(revision bc50fc42c6550ecdf5e89f83b811c2db9ff38684)
+++ kernel/generic/include/syscall/syscall.h	(revision 32099239a6124d59220f89570e99659141d22ed7)
@@ -51,5 +51,5 @@
 	SYS_IPC_CALL_SYNC_SLOW,
 	SYS_IPC_CALL_ASYNC_FAST,
-	SYS_IPC_CALL_ASYNC,
+	SYS_IPC_CALL_ASYNC_SLOW,
 	SYS_IPC_ANSWER_FAST,
 	SYS_IPC_ANSWER,
Index: kernel/generic/src/ipc/sysipc.c
===================================================================
--- kernel/generic/src/ipc/sysipc.c	(revision bc50fc42c6550ecdf5e89f83b811c2db9ff38684)
+++ kernel/generic/src/ipc/sysipc.c	(revision 32099239a6124d59220f89570e99659141d22ed7)
@@ -445,6 +445,6 @@
 /** Make a fast asynchronous call over IPC.
  *
- * This function can only handle two arguments of payload, but is faster than
- * the generic function sys_ipc_call_async().
+ * This function can only handle four arguments of payload, but is faster than
+ * the generic function sys_ipc_call_async_slow().
  *
  * @param phoneid	Phone handle for the call.
@@ -452,4 +452,6 @@
  * @param arg1		Service-defined payload argument.
  * @param arg2		Service-defined payload argument.
+ * @param arg3		Service-defined payload argument.
+ * @param arg4		Service-defined payload argument.
  *
  * @return 		Return call hash on success.
@@ -459,5 +461,5 @@
  */
 unative_t sys_ipc_call_async_fast(unative_t phoneid, unative_t method,
-    unative_t arg1, unative_t arg2)
+    unative_t arg1, unative_t arg2, unative_t arg3, unative_t arg4)
 {
 	call_t *call;
@@ -474,5 +476,6 @@
 	IPC_SET_ARG1(call->data, arg1);
 	IPC_SET_ARG2(call->data, arg2);
-	IPC_SET_ARG3(call->data, 0);
+	IPC_SET_ARG3(call->data, arg3);
+	IPC_SET_ARG4(call->data, arg4);
 
 	if (!(res = request_preprocess(call)))
@@ -491,5 +494,5 @@
  * @return		See sys_ipc_call_async_fast(). 
  */
-unative_t sys_ipc_call_async(unative_t phoneid, ipc_data_t *data)
+unative_t sys_ipc_call_async_slow(unative_t phoneid, ipc_data_t *data)
 {
 	call_t *call;
Index: kernel/generic/src/syscall/syscall.c
===================================================================
--- kernel/generic/src/syscall/syscall.c	(revision bc50fc42c6550ecdf5e89f83b811c2db9ff38684)
+++ kernel/generic/src/syscall/syscall.c	(revision 32099239a6124d59220f89570e99659141d22ed7)
@@ -136,5 +136,5 @@
 	(syshandler_t) sys_ipc_call_sync_slow,
 	(syshandler_t) sys_ipc_call_async_fast,
-	(syshandler_t) sys_ipc_call_async,
+	(syshandler_t) sys_ipc_call_async_slow,
 	(syshandler_t) sys_ipc_answer_fast,
 	(syshandler_t) sys_ipc_answer,