diff --git a/Lib/doctest.py b/Lib/doctest.py
index 3eb904e..783b456 100644
--- a/Lib/doctest.py
+++ b/Lib/doctest.py
@@ -793,7 +793,7 @@
 
         The optional argument `doctest_factory` specifies a class or
         function that should be used to create new DocTest objects (or
-        objects that implement the same interface as DocTest).  This
+        objects that implement the same interface as DocTest).  The
         signature for this factory function should match the signature
         of the DocTest constructor.