diff --git a/src/postorius/middleware.py b/src/postorius/middleware.py
index 2c1f874..4dc9f59 100644
--- a/src/postorius/middleware.py
+++ b/src/postorius/middleware.py
@@ -20,10 +20,12 @@
 
 from postorius import utils
 from postorius.models import MailmanApiError
+from mailmanclient import MailmanConnectionError
 
 
 class PostoriusMiddleware(object):
 
     def process_exception(self, request, exception):
-        if isinstance(exception, MailmanApiError):
+        if isinstance(exception, MailmanApiError) or isinstance(
+                exception, MailmanConnectionError):
             return utils.render_api_error(request)