diff --git a/include/winbase.h b/include/winbase.h
index a317a98..ba207f1 100644
--- a/include/winbase.h
+++ b/include/winbase.h
@@ -189,6 +189,8 @@
 #define DRIVE_CDROM                5
 #define DRIVE_RAMDISK              6
 
+#define MAX_COMPUTERNAME_LENGTH    31
+
 /* The security attributes structure */
 typedef struct _SECURITY_ATTRIBUTES
 {