diff --git a/contrib/postgres_fdw/connection.c b/contrib/postgres_fdw/connection.c
index b4fa89bce906319aaa4bb39f21ba983d5d6ef7d3..0b07a86a6aee5d26673aba3901b141d7ea561376 100644
--- a/contrib/postgres_fdw/connection.c
+++ b/contrib/postgres_fdw/connection.c
@@ -741,17 +741,17 @@ 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 7c922821e988ffde8711e8323ff310c8166187d4..48e0ad2756399451315020ff3a2e90dea95b5d9c 100644
--- a/doc/src/sgml/postgres-fdw.sgml
+++ b/doc/src/sgml/postgres-fdw.sgml
@@ -415,6 +415,12 @@
    COMMITTED</> 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>