diff --git a/briar_wrapper/api_thread.py b/briar_wrapper/api_thread.py
index 18b5928..7b922b8 100644
--- a/briar_wrapper/api_thread.py
+++ b/briar_wrapper/api_thread.py
@@ -60,6 +60,8 @@ class ApiThread:
                 if http_error.code == 404:
                     return self._api.on_successful_startup(callback)
             except URLError as url_error:
-                if not isinstance(url_error.reason, ConnectionRefusedError):
+                if (not isinstance(url_error.reason, ConnectionRefusedError)
+                        and (isinstance(url_error.reason, OSError)
+                             and url_error.reason.errno != 99)):
                     raise url_error
         callback(False)