diff --git a/lib/concurrent/actor/behaviour/supervised.rb b/lib/concurrent/actor/behaviour/supervised.rb
index db67cc0dc..720959413 100644
--- a/lib/concurrent/actor/behaviour/supervised.rb
+++ b/lib/concurrent/actor/behaviour/supervised.rb
@@ -2,7 +2,7 @@ module Concurrent
   module Actor
     module Behaviour
 
-      # Sets nad holds the supervisor of the actor if any. There is only one or none supervisor
+      # Sets and holds the supervisor of the actor if any. There is at most one supervisor
       # for each actor. Each supervisor is automatically linked.
       class Supervised < Abstract
         attr_reader :supervisor