diff --git a/lib/Migration/Version2001Date20180103144447.php b/lib/Migration/Version2001Date20180103144447.php
index 0af9e898bda..fc2d6206a34 100644
--- a/lib/Migration/Version2001Date20180103144447.php
+++ b/lib/Migration/Version2001Date20180103144447.php
@@ -94,7 +94,7 @@ public function changeSchema(IOutput $output, \Closure $schemaClosure, array $op
 			$table->addColumn('session_id', Type::STRING, [
 				'notnull' => true,
 				'length' => 255,
-				'default' => '',
+				'default' => '0',
 			]);
 			$table->addColumn('participant_type', Type::SMALLINT, [
 				'notnull' => true,