1 files changed, 9 insertions, 6 deletions

diff --git a/src/mailman/app/subscriptions.py b/src/mailman/app/subscriptions.py
index cc28ea859..a0c0c8059 100644
--- a/src/mailman/app/subscriptions.py
+++ b/src/mailman/app/subscriptions.py
@@ -17,6 +17,7 @@
 
 """Handle subscriptions."""
 
+from mailman.config import config
 from mailman.database.transaction import flush
 from mailman.interfaces.listmanager import ListDeletingEvent
 from mailman.interfaces.pending import IPendings
@@ -56,11 +57,13 @@ class SubscriptionManager:
         if pendable is None:
             raise LookupError
         workflow_type = pendable.get('type')
-        assert workflow_type in (PendableSubscription.PEND_TYPE,
-                                 PendableUnsubscription.PEND_TYPE)
-        workflow = (self._mlist.subscription_policy
-                    if workflow_type == PendableSubscription.PEND_TYPE
-                    else self._mlist.unsubscription_policy)(self._mlist)
+        if workflow_type in {PendableSubscription.PEND_TYPE,
+                             PendableUnsubscription.PEND_TYPE}:
+            workflow = (self._mlist.subscription_policy
+                        if workflow_type == PendableSubscription.PEND_TYPE
+                        else self._mlist.unsubscription_policy)(self._mlist)
+        else:
+            workflow = config.workflows[workflow_type](self._mlist)
         workflow.token = token
         workflow.restore()
         # In order to just run the whole workflow, all we need to do
@@ -84,6 +87,6 @@ def handle_ListDeletingEvent(event):
         return
     # Find all the members still associated with the mailing list.
     members = getUtility(ISubscriptionService).find_members(
-        list_id=event.mailing_list.list_id)
+            list_id=event.mailing_list.list_id)
     for member in members:
         member.unsubscribe()