Index: uspace/lib/libc/include/ipc/ipc.h
===================================================================
--- uspace/lib/libc/include/ipc/ipc.h	(revision f2ef7fd587b7ec8f9d3293862101dfa7dbf2ecf6)
+++ uspace/lib/libc/include/ipc/ipc.h	(revision 5045a683db1d22280b55badb1008a62177d3cb83)
@@ -284,6 +284,7 @@
 extern int ipc_data_read_start(int phoneid, void *dst, size_t size);
 extern int ipc_data_read_receive(ipc_callid_t *callid, size_t *size);
-extern int ipc_data_read_finalize(ipc_callid_t callid, void *src, size_t size);
-extern int ipc_data_write_start(int phoneid, void *src, size_t size);
+extern int ipc_data_read_finalize(ipc_callid_t callid, const void *src,
+    size_t size);
+extern int ipc_data_write_start(int phoneid, const void *src, size_t size);
 extern int ipc_data_write_receive(ipc_callid_t *callid, size_t *size);
 extern int ipc_data_write_finalize(ipc_callid_t callid, void *dst, size_t size);