diff --git a/app/models/notifier.rb b/app/models/notifier.rb
index 81e69ce07..24c1b3b4e 100644
--- a/app/models/notifier.rb
+++ b/app/models/notifier.rb
@@ -14,7 +14,8 @@ class Notifier
 
   def notify
     if should_notify?
-      recipients.map do |recipient|
+      # Processing recipients in order avoids deadlocks if notifications overlap.
+      recipients.sort_by(&:id).map do |recipient|
         Notification.create! user: recipient, source: source, creator: creator
       end
     end