diff --git a/src/datasource-zabbix/migrations.js b/src/datasource-zabbix/migrations.js
index 0bbd737..9429211 100644
--- a/src/datasource-zabbix/migrations.js
+++ b/src/datasource-zabbix/migrations.js
@@ -34,5 +34,9 @@ export function migrate(target) {
 }
 
 function convertToRegex(str) {
-  return '/' + str + '/';
+  if (str) {
+    return '/' + str + '/';
+  } else {
+    return '/.*/';
+  }
 }