diff --git a/mktxp/datasource/system_resource_ds.py b/mktxp/datasource/system_resource_ds.py
index 250ccd2..d2c783d 100644
--- a/mktxp/datasource/system_resource_ds.py
+++ b/mktxp/datasource/system_resource_ds.py
@@ -34,7 +34,7 @@ class SystemResourceMetricsDataSource:
     def is_os_with_wifi_builtin(router_entry):
         try:
             system_resource_records = router_entry.api_connection.router_api().get_resource('/system/resource').get()
-            version = ''
+            version = None
             for record in system_resource_records:
                 if record['version']:
                     version = record['version']
@@ -45,4 +45,4 @@ class SystemResourceMetricsDataSource:
             return is_wifi_version(version)
         except Exception as exc:
             print(f'Error getting system resource info from router{router_entry.router_name}@{router_entry.config_entry.hostname}: {exc}')
-        return False
\ No newline at end of file
+        return False