diff --git a/acme-copy-certs/app/service_manager.py b/acme-copy-certs/app/service_manager.py
index ba1b078ee351aadd2ad1e9878e4031b5d309a23b..d5ef1d68820ff5b1b100eacc039d8ac0461576a1 100644
--- a/acme-copy-certs/app/service_manager.py
+++ b/acme-copy-certs/app/service_manager.py
@@ -120,7 +120,7 @@ class ServicesManager:
             host = service.host
             self.services_by_host[host].remove(service)
             del self.services_by_id[id]
-            if len(self.services_by_host[host] == 0):
+            if len(self.services_by_host[host]) == 0:
                 del self.services_by_host[host]
                 self.updater.remove(host)