diff --git a/pg_ivm--1.0.sql b/pg_ivm--1.0.sql
index d9c6181..3fd9503 100644
--- a/pg_ivm--1.0.sql
+++ b/pg_ivm--1.0.sql
@@ -19,6 +19,7 @@ SELECT pg_catalog.pg_extension_config_dump('pg_catalog.pg_ivm_immv', '');
 
 CREATE FUNCTION create_immv(text, text)
 RETURNS bigint 
+STRICT
 AS 'MODULE_PATHNAME', 'create_immv'
 LANGUAGE C;