diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
index 10e8dbc9b1..588c0841fe 100644
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -1006,24 +1006,18 @@ static const SchemaQuery Query_for_trigger_of_table = {
 
 /* Use COMPLETE_WITH_QUERY_VERBATIM with these queries for GUC names: */
 #define Query_for_list_of_alter_system_set_vars \
-"SELECT name FROM "\
-" (SELECT pg_catalog.lower(name) AS name FROM pg_catalog.pg_settings "\
-"  WHERE context != 'internal' "\
-" ) ss "\
-" WHERE name LIKE '%s'"
+"SELECT pg_catalog.lower(name) FROM pg_catalog.pg_settings "\
+" WHERE context != 'internal' "\
+"   AND pg_catalog.lower(name) LIKE pg_catalog.lower('%s')"
 
 #define Query_for_list_of_set_vars \
-"SELECT name FROM "\
-" (SELECT pg_catalog.lower(name) AS name FROM pg_catalog.pg_settings "\
-"  WHERE context IN ('user', 'superuser') "\
-" ) ss "\
-" WHERE name LIKE '%s'"
+"SELECT pg_catalog.lower(name) FROM pg_catalog.pg_settings "\
+" WHERE context IN ('user', 'superuser') "\
+"   AND pg_catalog.lower(name) LIKE pg_catalog.lower('%s')"
 
 #define Query_for_list_of_show_vars \
-"SELECT name FROM "\
-" (SELECT pg_catalog.lower(name) AS name FROM pg_catalog.pg_settings "\
-" ) ss "\
-" WHERE name LIKE '%s'"
+"SELECT pg_catalog.lower(name) FROM pg_catalog.pg_settings "\
+" WHERE pg_catalog.lower(name) LIKE pg_catalog.lower('%s')"
 
 #define Query_for_list_of_roles \
 " SELECT rolname "\