diff --git a/contrib/postgres_fdw/expected/postgres_fdw.out b/contrib/postgres_fdw/expected/postgres_fdw.out
index a5c70d1bd18..b778bdbb5ce 100644
--- a/contrib/postgres_fdw/expected/postgres_fdw.out
+++ b/contrib/postgres_fdw/expected/postgres_fdw.out
@@ -1064,6 +1064,26 @@ SELECT * FROM ft1 t1 WHERE t1.c1 === t1.c2 order by t1.c2 limit 1;
1 | 1 | 00001 | Fri Jan 02 00:00:00 1970 PST | Fri Jan 02 00:00:00 1970 | 1 | 1 | foo
(1 row)
+-- check schema-qualification of regconfig constant
+CREATE TEXT SEARCH CONFIGURATION public.custom_search
+ (COPY = pg_catalog.english);
+EXPLAIN (VERBOSE, COSTS OFF)
+SELECT c1, to_tsvector('custom_search'::regconfig, c3) FROM ft1
+WHERE c1 = 642 AND length(to_tsvector('custom_search'::regconfig, c3)) > 0;
+ QUERY PLAN
+----------------------------------------------------------------------------------------------------------------------------------------------
+ Foreign Scan on public.ft1
+ Output: c1, to_tsvector('custom_search'::regconfig, c3)
+ Remote SQL: SELECT "C 1", c3 FROM "S 1"."T 1" WHERE (("C 1" = 642)) AND ((length(to_tsvector('public.custom_search'::regconfig, c3)) > 0))
+(3 rows)
+
+SELECT c1, to_tsvector('custom_search'::regconfig, c3) FROM ft1
+WHERE c1 = 642 AND length(to_tsvector('custom_search'::regconfig, c3)) > 0;
+ c1 | to_tsvector
+-----+-------------
+ 642 | '00642':1
+(1 row)
+
-- ===================================================================
-- JOIN queries
-- ===================================================================
diff --git a/contrib/postgres_fdw/postgres_fdw.c b/contrib/postgres_fdw/postgres_fdw.c
index 3dc717c4737..fb8cd37fb68 100644
--- a/contrib/postgres_fdw/postgres_fdw.c
+++ b/contrib/postgres_fdw/postgres_fdw.c
@@ -3495,6 +3495,14 @@ set_transmission_modes(void)
PGC_USERSET, PGC_S_SESSION,
GUC_ACTION_SAVE, true, 0, false);
+ /*
+ * In addition force restrictive search_path, in case there are any
+ * regproc or similar constants to be printed.
+ */
+ (void) set_config_option("search_path", "pg_catalog",
+ PGC_USERSET, PGC_S_SESSION,
+ GUC_ACTION_SAVE, true, 0, false);
+
return nestlevel;
}
diff --git a/contrib/postgres_fdw/sql/postgres_fdw.sql b/contrib/postgres_fdw/sql/postgres_fdw.sql
index 808ce6f0726..55cda85c77e 100644
--- a/contrib/postgres_fdw/sql/postgres_fdw.sql
+++ b/contrib/postgres_fdw/sql/postgres_fdw.sql
@@ -398,6 +398,15 @@ EXPLAIN (VERBOSE, COSTS OFF)
SELECT * FROM ft1 t1 WHERE t1.c1 === t1.c2 order by t1.c2 limit 1;
SELECT * FROM ft1 t1 WHERE t1.c1 === t1.c2 order by t1.c2 limit 1;
+-- check schema-qualification of regconfig constant
+CREATE TEXT SEARCH CONFIGURATION public.custom_search
+ (COPY = pg_catalog.english);
+EXPLAIN (VERBOSE, COSTS OFF)
+SELECT c1, to_tsvector('custom_search'::regconfig, c3) FROM ft1
+WHERE c1 = 642 AND length(to_tsvector('custom_search'::regconfig, c3)) > 0;
+SELECT c1, to_tsvector('custom_search'::regconfig, c3) FROM ft1
+WHERE c1 = 642 AND length(to_tsvector('custom_search'::regconfig, c3)) > 0;
+
-- ===================================================================
-- JOIN queries
-- ===================================================================