--- linux/include/linux/unistd.h
+++ linux/include/linux/unistd.h
@@ -1,7 +1,7 @@
 #ifndef _LINUX_UNISTD_H_
 #define _LINUX_UNISTD_H_
 
-extern int errno;
+#include <errno.h>
 
 /*
  * Include machine specific syscallX macros