--- IO-AIO/AIO.xs	2018/07/18 00:57:55	1.258
+++ IO-AIO/AIO.xs	2018/07/22 20:39:19	1.259
@@ -1044,6 +1044,8 @@
     const_niv (MADV_DONTNEED  , POSIX_MADV_DONTNEED)
 
     /* the second block will be 0 when missing */
+    const_iv (O_ACCMODE)
+
     const_iv (O_RDONLY)
     const_iv (O_WRONLY)
     const_iv (O_RDWR)