diff --git a/README.md b/README.md
index 8f51ff50..ddd28a1c 100644
--- a/README.md
+++ b/README.md
@@ -50,6 +50,8 @@ All notable changes to this project will be documented in this file. The format
 
 ## [Unreleased]
 
+## [4.0.0] - 2022-08-07
+
 ### Added
 - Add `SolidBody.evaluate.kirchhoff_stress()` method. Contrary to the Cauchy stress method, this gives correct results in incompressible plane stress.
 - Add `SolidBodyTensor` for tensor-based material definitions with state variables.
diff --git a/felupe/__about__.py b/felupe/__about__.py
index f5f41e56..ce1305bf 100644
--- a/felupe/__about__.py
+++ b/felupe/__about__.py
@@ -1 +1 @@
-__version__ = "3.1.0"
+__version__ = "4.0.0"
diff --git a/pyproject.toml b/pyproject.toml
index fde5b389..6c1c1f19 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "felupe"
-version = "3.1.0"
+version = "4.0.0"
 description = "Finite Element Analysis"
 readme = "README.md"
 requires-python = ">=3.6"
diff --git a/setup.cfg b/setup.cfg
index 9d96305d..4623cb5d 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -1,6 +1,6 @@
 [metadata]
 name = felupe
-version = 3.1.0
+version = 4.0.0
 author = Andreas Dutzler
 author_email = a.dutzler@gmail.com
 description = Finite Element Analysis