Fix typo.
diff --git a/Doc/library/unittest.rst b/Doc/library/unittest.rst
index 10e415b..01a036d 100644
--- a/Doc/library/unittest.rst
+++ b/Doc/library/unittest.rst
@@ -191,7 +191,7 @@
 
 .. _unittest-command-line-interface:
 
-Command Line Interface
+Command-Line Interface
 ----------------------
 
 The unittest module can be used from the command line to run tests from