document individual 2to3 fixers
diff --git a/Doc/tools/sphinxext/pyspecific.py b/Doc/tools/sphinxext/pyspecific.py
index fefe1c1..e6f8d43 100644
--- a/Doc/tools/sphinxext/pyspecific.py
+++ b/Doc/tools/sphinxext/pyspecific.py
@@ -124,3 +124,4 @@
     app.add_builder(suspicious.CheckSuspiciousMarkupBuilder)
     app.add_description_unit('opcode', 'opcode', '%s (opcode)',
                              parse_opcode_signature)
+    app.add_description_unit('2to3fixer', '2to3fixer', '%s (2to3 fixer)')