diff --git a/src/include/storage/proc.h b/src/include/storage/proc.h
index c3b462c..0c29037 100644
--- a/src/include/storage/proc.h
+++ b/src/include/storage/proc.h
@@ -204,6 +204,7 @@ typedef struct PGXACT
 								 * previously called InCommit */
 
 	uint8		nxids;
+	char		pad[52];
 } PGXACT;
 
 /*