#1548: fix apostroph placement.
diff --git a/Doc/using/cmdline.rst b/Doc/using/cmdline.rst
index 84d84e2..5f6bda5 100644
--- a/Doc/using/cmdline.rst
+++ b/Doc/using/cmdline.rst
@@ -10,7 +10,7 @@
 
 .. note:: 
    
-   Other implementation's command line schemes may differ.  See
+   Other implementations' command line schemes may differ.  See
    :ref:`implementations` for further resources.