* checking the hint bits.
  */
 TransactionId
-HeapTupleGetUpdateXid(HeapTupleHeader tuple)
+HeapTupleGetUpdateXid(const HeapTupleHeaderData *tup)
 {
-   return MultiXactIdGetUpdateXid(HeapTupleHeaderGetRawXmax(tuple),
-                                  tuple->t_infomask);
+   return MultiXactIdGetUpdateXid(HeapTupleHeaderGetRawXmax(tup),
+                                  tup->t_infomask);
 }
 
 /*
 
  */
 
 CommandId
-HeapTupleHeaderGetCmin(HeapTupleHeader tup)
+HeapTupleHeaderGetCmin(const HeapTupleHeaderData *tup)
 {
    CommandId   cid = HeapTupleHeaderGetRawCommandId(tup);
 
 }
 
 CommandId
-HeapTupleHeaderGetCmax(HeapTupleHeader tup)
+HeapTupleHeaderGetCmax(const HeapTupleHeaderData *tup)
 {
    CommandId   cid = HeapTupleHeaderGetRawCommandId(tup);
 
  * changes the tuple in shared buffers.
  */
 void
-HeapTupleHeaderAdjustCmax(HeapTupleHeader tup,
+HeapTupleHeaderAdjustCmax(const HeapTupleHeaderData *tup,
                          CommandId *cmax,
                          bool *iscombo)
 {
 
 #define HeapTupleIsValid(tuple) PointerIsValid(tuple)
 
 /* HeapTupleHeader functions implemented in utils/time/combocid.c */
-extern CommandId HeapTupleHeaderGetCmin(HeapTupleHeader tup);
-extern CommandId HeapTupleHeaderGetCmax(HeapTupleHeader tup);
-extern void HeapTupleHeaderAdjustCmax(HeapTupleHeader tup,
+extern CommandId HeapTupleHeaderGetCmin(const HeapTupleHeaderData *tup);
+extern CommandId HeapTupleHeaderGetCmax(const HeapTupleHeaderData *tup);
+extern void HeapTupleHeaderAdjustCmax(const HeapTupleHeaderData *tup,
                                      CommandId *cmax, bool *iscombo);
 
 /* Prototype for HeapTupleHeader accessors in heapam.c */
-extern TransactionId HeapTupleGetUpdateXid(HeapTupleHeader tuple);
+extern TransactionId HeapTupleGetUpdateXid(const HeapTupleHeaderData *tup);
 
 #endif                         /* HTUP_H */