diff --git a/contrib/postgres_fdw/t/010_subscription.pl b/contrib/postgres_fdw/t/010_subscription.pl
index 163c788d209..c34b3d15b8d 100644
--- a/contrib/postgres_fdw/t/010_subscription.pl
+++ b/contrib/postgres_fdw/t/010_subscription.pl
@@ -99,4 +99,49 @@ $result =
 is($result, qq(1073),
 	'check subscription after ALTER SUBSCRIPTION ... SERVER');
 
+# Check that REASSIGN OWNED processes a subscription only when run in the
+# database to which the subscription belongs.
+$node_subscriber->safe_psql(
+	'postgres', q{
+	CREATE ROLE regress_sub_old;
+	CREATE ROLE regress_sub_new;
+	GRANT pg_create_subscription TO regress_sub_old;
+	CREATE DATABASE regress_sub_db;
+});
+
+$node_subscriber->safe_psql(
+	'regress_sub_db', qq{
+	CREATE EXTENSION postgres_fdw;
+	CREATE SERVER regress_sub_server FOREIGN DATA WRAPPER postgres_fdw
+		OPTIONS (host '$publisher_host', port '$publisher_port', dbname 'postgres');
+	CREATE USER MAPPING FOR regress_sub_old SERVER regress_sub_server
+		OPTIONS (user 'unused', password 'secret');
+	CREATE USER MAPPING FOR regress_sub_new SERVER regress_sub_server
+		OPTIONS (user 'unused', password 'secret');
+	GRANT USAGE ON FOREIGN SERVER regress_sub_server
+		TO regress_sub_old, regress_sub_new;
+	GRANT CREATE ON DATABASE regress_sub_db TO regress_sub_old;
+	SET SESSION AUTHORIZATION regress_sub_old;
+	CREATE SUBSCRIPTION regress_sub SERVER regress_sub_server
+		PUBLICATION tap_pub WITH (connect = false, slot_name = NONE);
+});
+
+$node_subscriber->safe_psql('postgres',
+	'REASSIGN OWNED BY regress_sub_old TO regress_sub_new');
+$result = $node_subscriber->safe_psql(
+	'postgres',
+	q{SELECT subowner::regrole FROM pg_subscription
+	  WHERE subname = 'regress_sub'});
+is($result, 'regress_sub_old',
+	'REASSIGN OWNED in another database skips subscription');
+
+$node_subscriber->safe_psql('regress_sub_db',
+	'REASSIGN OWNED BY regress_sub_old TO regress_sub_new');
+$result = $node_subscriber->safe_psql(
+	'regress_sub_db',
+	q{SELECT subowner::regrole FROM pg_subscription
+	  WHERE subname = 'regress_sub'});
+is($result, 'regress_sub_new',
+	'REASSIGN OWNED in subscription database changes owner');
+
 done_testing();
diff --git a/doc/src/sgml/ref/reassign_owned.sgml b/doc/src/sgml/ref/reassign_owned.sgml
index ab692bd0690..5fca2329de2 100644
--- a/doc/src/sgml/ref/reassign_owned.sgml
+++ b/doc/src/sgml/ref/reassign_owned.sgml
@@ -48,7 +48,10 @@ REASSIGN OWNED BY { <replaceable class="parameter">old_role</replaceable> | CURR
       The name of a role. The ownership of all the objects within the
       current database, and of all shared objects (databases, tablespaces),
       owned by this role will be reassigned to
-      <replaceable class="parameter">new_role</replaceable>.
+      <replaceable class="parameter">new_role</replaceable>. Subscriptions,
+      although stored in a shared catalog, belong to a specific database
+      and are reassigned only when <command>REASSIGN OWNED</command> is executed
+      in that database.
      </para>
     </listitem>
    </varlistentry>
diff --git a/doc/src/sgml/user-manag.sgml b/doc/src/sgml/user-manag.sgml
index d68dd261012..1663794caec 100644
--- a/doc/src/sgml/user-manag.sgml
+++ b/doc/src/sgml/user-manag.sgml
@@ -530,7 +530,9 @@ ALTER TABLE bobs_table OWNER TO alice;
    that contains objects owned by the role.  (Note that the first
    such <command>REASSIGN OWNED</command> will change the ownership of any
    shared-across-databases objects, that is databases or tablespaces, that
-   are owned by the role-to-be-dropped.)
+   are owned by the role-to-be-dropped. Subscriptions, while stored in a
+   shared catalog, belong to a specific database and are reassigned only when
+   <command>REASSIGN OWNED</command> is executed in that database.)
   </para>
 
   <para>
diff --git a/src/backend/catalog/pg_subscription.c b/src/backend/catalog/pg_subscription.c
index b5cb301db88..d1a110f1ff3 100644
--- a/src/backend/catalog/pg_subscription.c
+++ b/src/backend/catalog/pg_subscription.c
@@ -114,6 +114,12 @@ GetSubscription(Oid subid, bool missing_ok, bool conninfo_needed,
 
 	subform = (Form_pg_subscription) GETSTRUCT(tup);
 
+	/*
+	 * It's only safe to access subscriptions from another database from the
+	 * launcher process, which does not call GetSubscription().
+	 */
+	Assert(subform->subdbid == MyDatabaseId);
+
 	sub = palloc0_object(Subscription);
 	sub->cxt = cxt;
 	sub->oid = subid;
@@ -265,6 +271,9 @@ DisableSubscription(Oid subid)
 	if (!HeapTupleIsValid(tup))
 		elog(ERROR, "cache lookup failed for subscription %u", subid);
 
+	/* Must only modify subscriptions belonging to the current database. */
+	Assert(((Form_pg_subscription) GETSTRUCT(tup))->subdbid == MyDatabaseId);
+
 	LockSharedObject(SubscriptionRelationId, subid, 0, AccessShareLock);
 
 	/* Form a new tuple. */
@@ -707,6 +716,9 @@ UpdateDeadTupleRetentionStatus(Oid subid, bool active)
 	if (!HeapTupleIsValid(tup))
 		elog(ERROR, "cache lookup failed for subscription %u", subid);
 
+	/* Must only modify subscriptions belonging to the current database. */
+	Assert(((Form_pg_subscription) GETSTRUCT(tup))->subdbid == MyDatabaseId);
+
 	LockSharedObject(SubscriptionRelationId, subid, 0, AccessShareLock);
 
 	/* Form a new tuple. */
diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index ee06a726f42..1284d410790 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -2665,6 +2665,9 @@ AlterSubscriptionOwner_internal(Relation rel, HeapTuple tup, Oid newOwnerId)
 
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 
+	/* Must only alter subscriptions belonging to the current database. */
+	Assert(form->subdbid == MyDatabaseId);
+
 	if (form->subowner == newOwnerId)
 		return;
 
@@ -2779,6 +2782,7 @@ AlterSubscriptionOwner_oid(Oid subid, Oid newOwnerId)
 {
 	HeapTuple	tup;
 	Relation	rel;
+	Form_pg_subscription form;
 
 	rel = table_open(SubscriptionRelationId, RowExclusiveLock);
 
@@ -2789,7 +2793,15 @@ AlterSubscriptionOwner_oid(Oid subid, Oid newOwnerId)
 				(errcode(ERRCODE_UNDEFINED_OBJECT),
 				 errmsg("subscription with OID %u does not exist", subid)));
 
-	AlterSubscriptionOwner_internal(rel, tup, newOwnerId);
+	form = (Form_pg_subscription) GETSTRUCT(tup);
+
+	/*
+	 * Don't process subscriptions belonging to other databases. While
+	 * pg_subscription is a shared catalog, subscriptions refer to db-local
+	 * objects which exist only in the database identified by subdbid.
+	 */
+	if (form->subdbid == MyDatabaseId)
+		AlterSubscriptionOwner_internal(rel, tup, newOwnerId);
 
 	heap_freetuple(tup);