Index: uspace/lib/c/include/async.h
===================================================================
--- uspace/lib/c/include/async.h	(revision 4f13e19af6dd310dbc87a66e115ff6ac62b71bde)
+++ uspace/lib/c/include/async.h	(revision 046b66e808c359758d9021ead91cfb8804d60dfb)
@@ -33,10 +33,10 @@
  */
 
-#if ((defined(LIBC_IPC_H_)) && (!defined(LIBC_ASYNC_C_)))
+#if ((defined(_LIBC_IPC_H_)) && (!defined(_LIBC_ASYNC_C_)))
 #error Do not intermix low-level IPC interface and async framework
 #endif
 
-#ifndef LIBC_ASYNC_H_
-#define LIBC_ASYNC_H_
+#ifndef _LIBC_ASYNC_H_
+#define _LIBC_ASYNC_H_
 
 #include <ipc/common.h>