Index: uspace/lib/libc/generic/ipc.c
===================================================================
--- uspace/lib/libc/generic/ipc.c	(revision 60866a39276f095402ba62f4e3a3289af8ad446e)
+++ uspace/lib/libc/generic/ipc.c	(revision 287e83f9b1d052d373437f8888bca9dcebd88cfc)
@@ -705,5 +705,5 @@
 	IPC_SET_ARG5(data, arg5);
 
-	return __SYSCALL3(SYS_IPC_FORWARD_SLOW, callid, (sysarg_t) &data, mode);
+	return __SYSCALL4(SYS_IPC_FORWARD_SLOW, callid, phoneid, (sysarg_t) &data, mode);
 }