Index: uspace/lib/libc/include/ipc/ipc.h
===================================================================
--- uspace/lib/libc/include/ipc/ipc.h	(revision 4470e2627030413dc38c0d3b98d9c6a3e1672564)
+++ uspace/lib/libc/include/ipc/ipc.h	(revision 71f1cc1dd43b4489b3635e4b8c512aa23359d9b3)
@@ -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);