*** a/src/pl/plperl/expected/plperl_trigger.out
--- b/src/pl/plperl/expected/plperl_trigger.out
***************
*** 266,268 **** SELECT * FROM trigger_test;
--- 266,274 ----
   4 | immortal
  (1 row)
  
+ CREATE OR REPLACE FUNCTION direct_trigger() RETURNS trigger AS $$
+     return;
+ $$ LANGUAGE plperl;
+ SELECT direct_trigger();
+ ERROR:  trigger functions can only be called as triggers
+ CONTEXT:  compilation of PL/Perl function "direct_trigger"
*** a/src/pl/plperl/sql/plperl_trigger.sql
--- b/src/pl/plperl/sql/plperl_trigger.sql
***************
*** 130,132 **** DELETE FROM trigger_test;
--- 130,138 ----
  
  
  SELECT * FROM trigger_test;
+ 
+ CREATE OR REPLACE FUNCTION direct_trigger() RETURNS trigger AS $$
+     return;
+ $$ LANGUAGE plperl;
+ 
+ SELECT direct_trigger();