diff --git a/src/include/access/heapam.h b/src/include/access/heapam.h
index 4c0256b18a4..608f50b0616 100644
--- a/src/include/access/heapam.h
+++ b/src/include/access/heapam.h
@@ -53,23 +53,34 @@ typedef enum LockTupleMode
  * When heap_update, heap_delete, or heap_lock_tuple fail because the target
  * tuple is already outdated, they fill in this struct to provide information
  * to the caller about what happened.
+ *
+ * result is the result of HeapTupleSatisfiesUpdate, leading to the failure.
+ * It's set to HeapTupleMayBeUpdated when there is no failure.
+ *
  * ctid is the target's ctid link: it is the same as the target's TID if the
  * target was deleted, or the location of the replacement tuple if the target
  * was updated.
+ *
  * xmax is the outdating transaction's XID.  If the caller wants to visit the
  * replacement tuple, it must check that this matches before believing the
  * replacement is really a match.
+ *
  * cmax is the outdating command's CID, but only when the failure code is
  * HeapTupleSelfUpdated (i.e., something in the current transaction outdated
  * the tuple); otherwise cmax is zero.  (We make this restriction because
  * HeapTupleHeaderGetCmax doesn't work for tuples outdated in other
  * transactions.)
+ *
+ * lockmode is only relevant for callers of heap_update() and is the mode which
+ * the caller should use in case it needs to lock the updated tuple.
  */
 typedef struct HeapUpdateFailureData
 {
+   HTSU_Result result;
    ItemPointerData ctid;
    TransactionId xmax;
    CommandId   cmax;
+   LockTupleMode   lockmode;
 } HeapUpdateFailureData;