diff --git a/regress/expected/name_validation.out b/regress/expected/name_validation.out
index a9f804076..d0ba31ec1 100644
--- a/regress/expected/name_validation.out
+++ b/regress/expected/name_validation.out
@@ -475,6 +475,14 @@ NOTICE:  graph "graph123" has been dropped
  
 (1 row)
 
+--
+-- Test GUC names
+--
+SET age.enable_containment TO ON;
+SET age.invalid_parameter TO ON;
+ERROR:  invalid configuration parameter name "age.invalid_parameter"
+DETAIL:  "age" is a reserved prefix.
+SET any_placeholder.any_parameter TO ON;
 --
 -- End of test
 --
diff --git a/regress/sql/name_validation.sql b/regress/sql/name_validation.sql
index 0c96a25f2..acf782677 100644
--- a/regress/sql/name_validation.sql
+++ b/regress/sql/name_validation.sql
@@ -178,6 +178,13 @@ SELECT create_elabel('graph123', 'elabel0123456789012345678901234567890123456789
 -- clean up
 SELECT drop_graph('graph123', true);
 
+--
+-- Test GUC names
+--
+SET age.enable_containment TO ON;
+SET age.invalid_parameter TO ON;
+SET any_placeholder.any_parameter TO ON;
+
 --
 -- End of test
 --
diff --git a/src/backend/utils/ag_guc.c b/src/backend/utils/ag_guc.c
index d9a99f66e..86b4e00bc 100644
--- a/src/backend/utils/ag_guc.c
+++ b/src/backend/utils/ag_guc.c
@@ -42,4 +42,5 @@ void define_config_params(void)
                              NULL,
                              NULL,
                              NULL);
+    EmitWarningsOnPlaceholders("age");
 }