Bump to 3.9.0a0
diff --git a/Doc/tools/extensions/pyspecific.py b/Doc/tools/extensions/pyspecific.py
index 8bf7eb6..f79b250 100644
--- a/Doc/tools/extensions/pyspecific.py
+++ b/Doc/tools/extensions/pyspecific.py
@@ -36,7 +36,7 @@
 
 
 ISSUE_URI = 'https://bugs.python.org/issue%s'
-SOURCE_URI = 'https://github.com/python/cpython/tree/3.8/%s'
+SOURCE_URI = 'https://github.com/python/cpython/tree/master/%s'
 
 # monkey-patch reST parser to disable alphabetic and roman enumerated lists
 from docutils.parsers.rst.states import Body