diff --git a/docs/main/changelog.rst b/docs/main/changelog.rst
index 123b5a5a..d59a402c 100644
--- a/docs/main/changelog.rst
+++ b/docs/main/changelog.rst
@@ -9,6 +9,8 @@ follows `Semantic versioning`_
 
 Development version
 -------------------
+- Add support of six 1.14.0.
+- Add support of six 1.13.0.
 - Regenerate C sources using Cython 0.29.14.
 - Fix PEP257 doc block errors in example modules.
 
diff --git a/requirements.txt b/requirements.txt
index aa114e6f..c71dc73e 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1 +1 @@
-six>=1.7.0,<=1.13.0
+six>=1.7.0,<=1.14.0