diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index 80c183b235..13c871d2a8 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -7631,7 +7631,9 @@ SCRAM-SHA-256$<replaceable>&lt;iteration count&gt;</replaceable>:<replaceable>&l
        <structfield>srsublsn</structfield> <type>pg_lsn</type>
       </para>
       <para>
-       End LSN for <literal>s</literal> and <literal>r</literal> states.
+       Remote LSN of the state change used for synchronization coordination
+       when in <literal>s</literal> or <literal>r</literal> states,
+       otherwise null
       </para></entry>
      </row>
     </tbody>
diff --git a/src/backend/catalog/pg_subscription.c b/src/backend/catalog/pg_subscription.c
index e6afb3203e..90bf5cf0c6 100644
--- a/src/backend/catalog/pg_subscription.c
+++ b/src/backend/catalog/pg_subscription.c
@@ -452,13 +452,20 @@ GetSubscriptionRelations(Oid subid)
 	{
 		Form_pg_subscription_rel subrel;
 		SubscriptionRelState *relstate;
+		Datum		d;
+		bool		isnull;
 
 		subrel = (Form_pg_subscription_rel) GETSTRUCT(tup);
 
 		relstate = (SubscriptionRelState *) palloc(sizeof(SubscriptionRelState));
 		relstate->relid = subrel->srrelid;
 		relstate->state = subrel->srsubstate;
-		relstate->lsn = subrel->srsublsn;
+		d = SysCacheGetAttr(SUBSCRIPTIONRELMAP, tup,
+							Anum_pg_subscription_rel_srsublsn, &isnull);
+		if (isnull)
+			relstate->lsn = InvalidXLogRecPtr;
+		else
+			relstate->lsn = DatumGetLSN(d);
 
 		res = lappend(res, relstate);
 	}
@@ -504,13 +511,20 @@ GetSubscriptionNotReadyRelations(Oid subid)
 	{
 		Form_pg_subscription_rel subrel;
 		SubscriptionRelState *relstate;
+		Datum		d;
+		bool		isnull;
 
 		subrel = (Form_pg_subscription_rel) GETSTRUCT(tup);
 
 		relstate = (SubscriptionRelState *) palloc(sizeof(SubscriptionRelState));
 		relstate->relid = subrel->srrelid;
 		relstate->state = subrel->srsubstate;
-		relstate->lsn = subrel->srsublsn;
+		d = SysCacheGetAttr(SUBSCRIPTIONRELMAP, tup,
+							Anum_pg_subscription_rel_srsublsn, &isnull);
+		if (isnull)
+			relstate->lsn = InvalidXLogRecPtr;
+		else
+			relstate->lsn = DatumGetLSN(d);
 
 		res = lappend(res, relstate);
 	}
diff --git a/src/include/catalog/pg_subscription_rel.h b/src/include/catalog/pg_subscription_rel.h
index c44df04c72..f384f4e7fa 100644
--- a/src/include/catalog/pg_subscription_rel.h
+++ b/src/include/catalog/pg_subscription_rel.h
@@ -33,8 +33,18 @@ CATALOG(pg_subscription_rel,6102,SubscriptionRelRelationId)
 	Oid			srsubid;		/* Oid of subscription */
 	Oid			srrelid;		/* Oid of relation */
 	char		srsubstate;		/* state of the relation in subscription */
-	XLogRecPtr	srsublsn;		/* remote lsn of the state change used for
-								 * synchronization coordination */
+
+	/*
+	 * Although srsublsn is a fixed-width type, it is allowed to be NULL, so
+	 * we prevent direct C code access to it just as for a varlena field.
+	 */
+#ifdef CATALOG_VARLEN			/* variable-length fields start here */
+
+	XLogRecPtr	srsublsn BKI_FORCE_NULL;	/* remote LSN of the state change
+											 * used for synchronization
+											 * coordination, or NULL if not
+											 * valid */
+#endif
 } FormData_pg_subscription_rel;
 
 typedef FormData_pg_subscription_rel *Form_pg_subscription_rel;