--- openflow-2013-06-24-2.h	2015-07-23 09:54:17.548479378 -0700
+++ openflow-2013-07-09.h	2015-07-23 09:54:17.556479379 -0700
@@ -1246,9 +1246,9 @@
     uint16_t type;                  /* OFPAT_SET_FIELD. */
     uint16_t len;                   /* Length is padded to 64 bits. */
     /* Followed by:
-     *   - Exactly (len - 4) bytes containing a single OXM TLV, then
-     *   - Exactly (len + 7)/8*8 - len (between 0 and 7)
-     *     bytes of all-zero bytes
+     *   - Exactly (4 + oxm_length) bytes containing a single OXM TLV, then
+     *   - Exactly ((8 + oxm_length) + 7)/8*8 - (8 + oxm_length)
+     *     (between 0 and 7) bytes of all-zero bytes
      */
     uint8_t field[4];               /* OXM TLV - Make compiler happy */
 };