diff --git a/contrib/postgres_fdw/connection.c b/contrib/postgres_fdw/connection.c
index 7cd69cc709..077eaf46ee 100644
--- a/contrib/postgres_fdw/connection.c
+++ b/contrib/postgres_fdw/connection.c
@@ -725,7 +725,7 @@ pgfdw_xact_callback(XactEvent event, void *arg)
 					 */
 					ereport(ERROR,
 							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-							 errmsg("cannot prepare a transaction that modified remote tables")));
+							 errmsg("cannot prepare a transaction that has operated on postgres_fdw foreign tables")));
 					break;
 				case XACT_EVENT_PARALLEL_COMMIT:
 				case XACT_EVENT_COMMIT:
diff --git a/doc/src/sgml/postgres-fdw.sgml b/doc/src/sgml/postgres-fdw.sgml
index 634a7141ef..ed369cb54b 100644
--- a/doc/src/sgml/postgres-fdw.sgml
+++ b/doc/src/sgml/postgres-fdw.sgml
@@ -483,6 +483,12 @@
    COMMITTED</literal> local transaction.  A future
    <productname>PostgreSQL</productname> release might modify these rules.
   </para>
+
+  <para>
+   Note that it is currently not supported by
+   <filename>postgres_fdw</filename> to prepare the remote transaction for
+   two-phase commit.
+  </para>
  </sect2>
 
  <sect2>