diff --git a/src/main/h2/resources/sql/robot.ddl b/src/main/h2/resources/sql/robot.ddl
index f9525ff11..0a6295539 100644
--- a/src/main/h2/resources/sql/robot.ddl
+++ b/src/main/h2/resources/sql/robot.ddl
@@ -34,7 +34,7 @@ CREATE TABLE ACCESS_RESULT(
   MIME_TYPE VARCHAR(100) NOT NULL,
   CONTENT_LENGTH BIGINT NOT NULL,
   EXECUTION_TIME INTEGER NOT NULL,
-  LAST_MODIFIED TIMESTAMP NOT NULL,
+  LAST_MODIFIED TIMESTAMP,
   CREATE_TIME TIMESTAMP NOT NULL
 );