diff --git a/contrib/postgres_fdw/connection.c b/contrib/postgres_fdw/connection.c
index 57ed5f4b90..8f92e3be98 100644
--- a/contrib/postgres_fdw/connection.c
+++ b/contrib/postgres_fdw/connection.c
@@ -720,17 +720,17 @@ pgfdw_xact_callback(XactEvent event, void *arg)
 				case XACT_EVENT_PRE_PREPARE:
 
 					/*
-					 * We disallow remote transactions that modified anything,
-					 * since it's not very reasonable to hold them open until
-					 * the prepared transaction is committed.  For the moment,
-					 * throw error unconditionally; later we might allow
-					 * read-only cases.  Note that the error will cause us to
-					 * come right back here with event == XACT_EVENT_ABORT, so
-					 * we'll clean up the connection state at that point.
+					 * We disallow any remote transactions, since it's not
+					 * very reasonable to hold them open until the prepared
+					 * transaction is committed.  For the moment, throw error
+					 * unconditionally; later we might allow read-only cases.
+					 * Note that the error will cause us to come right back
+					 * here with event == XACT_EVENT_ABORT, so we'll clean up
+					 * the connection state at that point.
 					 */
 					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>