diff --git a/doc/api.rst b/doc/api.rst
index 193d1c707..b3191cad2 100644
--- a/doc/api.rst
+++ b/doc/api.rst
@@ -33,7 +33,7 @@ Utilities
 Notifier
 --------
 
-The Notifier object is used as a message distributor for a bus.
+The Notifier object is used as a message distributor for a bus. Notifier creates a thread to read messages from the bus and distributes them to listeners.
 
 .. autoclass:: can.Notifier
     :members: