diff --git a/src/include/storage/bufpage.h b/src/include/storage/bufpage.h
index d96e375..82cc592 100644
--- a/src/include/storage/bufpage.h
+++ b/src/include/storage/bufpage.h
@@ -156,6 +156,7 @@ typedef struct PageHeaderData
 	LocationIndex pd_special;	/* offset to start of special space */
 	uint16		pd_pagesize_version;
 	TransactionId pd_prune_xid; /* oldest prunable XID, or zero if none */
+	char		pd_padding[20];
 	ItemIdData	pd_linp[1];		/* beginning of line pointer array */
 } PageHeaderData;