Index: abi/include/_bits/errno.h
===================================================================
--- abi/include/_bits/errno.h	(revision 95174bfdc3425cbd2a229f8813c1b4c459e4a264)
+++ abi/include/_bits/errno.h	(revision a3f63ac154a8851b99a2cdc01fb73050f4b9ca43)
@@ -41,14 +41,20 @@
 #define _BITS_ERRNO_H_
 
+#include <_bits/native.h>
+#include <_bits/decls.h>
+
 #ifdef __OPAQUE_ERRNO__
 #include <_bits/__opaque_handle.h>
 
+__HELENOS_DECLS_BEGIN;
 __opaque_handle(errno_t);
 typedef errno_t sys_errno_t;
+__HELENOS_DECLS_END;
+
 #define __errno_t(val) ((errno_t) val)
 
 #else
 
-#include <_bits/native.h>
+__HELENOS_DECLS_BEGIN;
 
 /**
@@ -65,4 +71,6 @@
 typedef sysarg_t sys_errno_t;
 
+__HELENOS_DECLS_END;
+
 /**
  * A C++-style "cast" to `errno_t`.