diff --git a/README.rst b/README.rst
index 8c564f2..b727c70 100644
--- a/README.rst
+++ b/README.rst
@@ -66,7 +66,7 @@ Usage
 
     $ speedtest-cli -h
     usage: speedtest-cli [-h] [--share] [--simple] [--list] [--server SERVER]
-                         [--mini MINI] [--version]
+                         [--mini MINI] [--source SOURCE] [--version]
 
     Command line interface for testing internet bandwidth using speedtest.net.
     --------------------------------------------------------------------------
@@ -80,5 +80,6 @@ Usage
       --list           Display a list of speedtest.net servers sorted by distance
       --server SERVER  Specify a server ID to test against
       --mini MINI      URL of the Speedtest Mini server
+      --source SOURCE  Source IP address to bind to
       --version        Show the version number and exit