diff --git a/Doc/using/cmdline.rst b/Doc/using/cmdline.rst
index a34666d2dc5..12aa0f2393c 100644
--- a/Doc/using/cmdline.rst
+++ b/Doc/using/cmdline.rst
@@ -441,7 +441,7 @@ These environment variables influence Python's behavior.
 
 
 Debug-mode variables
-^^^^^^^^^^^^^^^^^^^^
+--------------------
 
 Setting these variables only has an effect in a debug build of Python, that is,
 if Python was configured with the :opt:`--with-pydebug` build option.