diff --git a/frappyman.py b/frappyman.py
index 4457c6a..104f3dd 100644
--- a/frappyman.py
+++ b/frappyman.py
@@ -382,7 +382,7 @@ class FrappyManager(ServiceManager):
         if running_addons:
             for cfg in running_addons.split(','):
                 seacfg = self.frappy2sea.get(cfg.strip())
-                if seacfg.endswith('.addon') and seacfg[:-6] not in sealist[2:]:
+                if seacfg is not None and seacfg.endswith('.addon') and seacfg[:-6] not in sealist[2:]:
                     proposed_cfg['addons'] = {running_addons}
                     break
         elif given_addons: