diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 2c517756c0..4cf5ffeedb 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -2305,7 +2305,7 @@ PrepareTransaction(void)
 	if ((MyXactFlags & XACT_FLAGS_ACCESSEDTEMPNAMESPACE))
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("cannot PREPARE a transaction that has operated on temporary namespace")));
+				 errmsg("cannot PREPARE a transaction that has operated on temporary objects")));
 
 	/*
 	 * Likewise, don't allow PREPARE after pg_export_snapshot.  This could be
diff --git a/src/test/modules/test_extensions/expected/test_extensions.out b/src/test/modules/test_extensions/expected/test_extensions.out
index 1eec5a37d3..b5cbdfcad4 100644
--- a/src/test/modules/test_extensions/expected/test_extensions.out
+++ b/src/test/modules/test_extensions/expected/test_extensions.out
@@ -148,7 +148,7 @@ SELECT create_extension_with_temp_schema();
 (1 row)
 
 PREPARE TRANSACTION 'twophase_extension';
-ERROR:  cannot PREPARE a transaction that has operated on temporary namespace
+ERROR:  cannot PREPARE a transaction that has operated on temporary objects
 -- Clean up
 DROP TABLE test_ext4_tab;
 DROP FUNCTION create_extension_with_temp_schema();
diff --git a/src/test/regress/expected/temp.out b/src/test/regress/expected/temp.out
index d6d8f25141..97fe478cae 100644
--- a/src/test/regress/expected/temp.out
+++ b/src/test/regress/expected/temp.out
@@ -310,19 +310,19 @@ begin;
 create function pg_temp.twophase_func() returns void as
   $$ select '2pc_func'::text $$ language sql;
 prepare transaction 'twophase_func';
-ERROR:  cannot PREPARE a transaction that has operated on temporary namespace
+ERROR:  cannot PREPARE a transaction that has operated on temporary objects
 -- Function drop
 create function pg_temp.twophase_func() returns void as
   $$ select '2pc_func'::text $$ language sql;
 begin;
 drop function pg_temp.twophase_func();
 prepare transaction 'twophase_func';
-ERROR:  cannot PREPARE a transaction that has operated on temporary namespace
+ERROR:  cannot PREPARE a transaction that has operated on temporary objects
 -- Operator creation
 begin;
 create operator pg_temp.@@ (leftarg = int4, rightarg = int4, procedure = int4mi);
 prepare transaction 'twophase_operator';
-ERROR:  cannot PREPARE a transaction that has operated on temporary namespace
+ERROR:  cannot PREPARE a transaction that has operated on temporary objects
 -- These generate errors about temporary tables.
 begin;
 create type pg_temp.twophase_type as (a int);
@@ -374,4 +374,4 @@ SELECT current_schema() ~ 'pg_temp' AS is_temp_schema;
 (1 row)
 
 PREPARE TRANSACTION 'twophase_search';
-ERROR:  cannot PREPARE a transaction that has operated on temporary namespace
+ERROR:  cannot PREPARE a transaction that has operated on temporary objects