diff --git a/dependency_injector/__init__.py b/dependency_injector/__init__.py
index 1d528b0e..6d016b57 100644
--- a/dependency_injector/__init__.py
+++ b/dependency_injector/__init__.py
@@ -1,6 +1,6 @@
 """Dependency injector top-level package."""
 
-VERSION = '2.1.0'
+VERSION = '2.1.1'
 """Version number that follows semantic versioning.
 
 :type: str
diff --git a/docs/main/changelog.rst b/docs/main/changelog.rst
index 26cb868d..3366a0ee 100644
--- a/docs/main/changelog.rst
+++ b/docs/main/changelog.rst
@@ -11,6 +11,10 @@ Development version
 -------------------
 - No features.
 
+2.1.1
+-----
+- Normalize package names by PEP-503.
+
 2.1.0
 -----
 - Add ``ThreadLocalSingleton`` and ``DelegatedThreadLocalSingleton`` providers.