diff --git a/lib/proposals_discussion_plugin/proposal_task.rb b/lib/proposals_discussion_plugin/proposal_task.rb
index f20fe5a..dbfaa2f 100644
--- a/lib/proposals_discussion_plugin/proposal_task.rb
+++ b/lib/proposals_discussion_plugin/proposal_task.rb
@@ -301,7 +301,8 @@ class ProposalsDiscussionPlugin::ProposalTask < Task
   end
 
   def proposal_source
-    article_parent.name
+    parent = article_parent
+    parent.name if parent
   end
 
   protected
--
libgit2 0.21.2