diff --git a/src/include/access/xact.h b/src/include/access/xact.h
index 503ae1b..a123d2a 100644
--- a/src/include/access/xact.h
+++ b/src/include/access/xact.h
@@ -225,7 +225,6 @@ typedef struct xl_xact_twophase
 {
 	TransactionId xid;
 } xl_xact_twophase;
-#define MinSizeOfXactInvals offsetof(xl_xact_invals, msgs)
 
 typedef struct xl_xact_origin
 {