diff --git a/CMakeLists.txt b/CMakeLists.txt
index 1dc06a8605..91a54ad206 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -28,7 +28,7 @@ set(MSVC_INCREMENTAL_DEFAULT ON)
 
 project(
   mujoco
-  VERSION 2.2.0
+  VERSION 2.2.1
   DESCRIPTION "MuJoCo Physics Simulator"
   HOMEPAGE_URL "https://mujoco.org"
 )
diff --git a/doc/changelog.rst b/doc/changelog.rst
index 4d645d9cd0..e57408ca99 100644
--- a/doc/changelog.rst
+++ b/doc/changelog.rst
@@ -2,14 +2,18 @@
 Changelog
 =========
 
-Upcoming version (not yet released)
------------------------------------
+.. Upcoming version (not yet released)
+.. -----------------------------------
+
+Version 2.2.1 (July 18, 2022)
+-----------------------------
 
 General
 ^^^^^^^
 
 - Added ``mjd_transitionFD`` to compute efficient finite difference approximations of the state-transition and
   control-transition matrices, :ref:`see here<derivatives>` for more details.
+- Added derivatives for the ellipsoid fluid model.
 - Added ``ctrl`` attribute to :ref:`keyframes<keyframe>`.
 - Added ``clock`` sensor which :ref:`measures time<sensor-clock>`.
 - Added visualisation groups to skins.
@@ -23,7 +27,7 @@ General
 - Add memory poisoning when building with Address Sanitizer (ASAN) and Memory Sanitizer (MSAN). This allows ASAN to
   detect reads and writes to regions in ``mjModel.buffer`` and ``mjData.buffer`` that do not lie within an array, and
   for MSAN to detect reads from uninitialised fields in ``mjData`` following ``mj_resetData``.
-
+- Add a `slider-crank example <https://github.com/deepmind/mujoco/tree/2.2.1/model/slider_crank>`_ to ``model/``.
 
 Bug fixes
 ^^^^^^^^^
diff --git a/doc/unity.rst b/doc/unity.rst
index d597d7c424..d5c8e711e8 100644
--- a/doc/unity.rst
+++ b/doc/unity.rst
@@ -29,14 +29,14 @@ _____
 
 The MuJoCo app needs to be run at least once before the native library can be used, in order to register the library as
 a trusted binary. Then, copy the dynamic library file from
-``/Applications/MuJoCo.app/Contents/Frameworks/mujoco.framework/Versions/Current/libmujoco.2.2.0.dylib`` (it can be
+``/Applications/MuJoCo.app/Contents/Frameworks/mujoco.framework/Versions/Current/libmujoco.2.2.1.dylib`` (it can be
 found by browsing the contents of ``MuJoCo.app``) and rename it as ``mujoco.dylib``.
 
 Linux
 _____
 
 Expand the ``tar.gz`` archive to ``~/.mujoco``. Then copy the dynamic library from
-``~/.mujoco/mujoco-2.2.0/lib/libmujoco.so.2.2.0`` and rename it as ``libmujoco.so``.
+``~/.mujoco/mujoco-2.2.1/lib/libmujoco.so.2.2.1`` and rename it as ``libmujoco.so``.
 
 Windows
 _______
diff --git a/include/mujoco/mujoco.h b/include/mujoco/mujoco.h
index 8b38f1107d..8434044a8e 100644
--- a/include/mujoco/mujoco.h
+++ b/include/mujoco/mujoco.h
@@ -24,7 +24,7 @@ extern "C" {
 #endif
 
 // header version; should match the library version as returned by mj_version()
-#define mjVERSION_HEADER 220
+#define mjVERSION_HEADER 221
 
 // needed to define size_t, fabs and log10
 #include "stdlib.h"
diff --git a/python/mujoco/CMakeLists.txt b/python/mujoco/CMakeLists.txt
index 9e5242f6b0..02bafd45c9 100644
--- a/python/mujoco/CMakeLists.txt
+++ b/python/mujoco/CMakeLists.txt
@@ -75,13 +75,13 @@ if(NOT TARGET mujoco)
     find_path(MUJOCO_FRAMEWORK mujoco.Framework HINTS ${MUJOCO_FRAMEWORK_DIR})
     if(MUJOCO_FRAMEWORK)
       message("MuJoCo framework is at ${MUJOCO_FRAMEWORK}/mujoco.framework")
-      set(MUJOCO_LIBRARY ${MUJOCO_FRAMEWORK}/mujoco.framework/Versions/A/libmujoco.2.2.0.dylib)
+      set(MUJOCO_LIBRARY ${MUJOCO_FRAMEWORK}/mujoco.framework/Versions/A/libmujoco.2.2.1.dylib)
       target_compile_options(mujoco INTERFACE -F${MUJOCO_FRAMEWORK})
     endif()
   endif()
 
   if(NOT MUJOCO_FRAMEWORK)
-    find_library(MUJOCO_LIBRARY mujoco mujoco.2.2.0 HINTS ${MUJOCO_LIBRARY_DIR} REQUIRED)
+    find_library(MUJOCO_LIBRARY mujoco mujoco.2.2.1 HINTS ${MUJOCO_LIBRARY_DIR} REQUIRED)
     find_path(MUJOCO_INCLUDE mujoco/mujoco.h HINTS ${MUJOCO_INCLUDE_DIR} REQUIRED)
     message("MuJoCo is at ${MUJOCO_LIBRARY}")
     message("MuJoCo headers are at ${MUJOCO_INCLUDE}")
diff --git a/python/setup.py b/python/setup.py
index 968a87448a..db41f30fe5 100644
--- a/python/setup.py
+++ b/python/setup.py
@@ -30,7 +30,7 @@
 from setuptools import setup
 from setuptools.command import build_ext
 
-__version__ = '2.2.0'
+__version__ = '2.2.1'
 
 MUJOCO_CMAKE = 'MUJOCO_CMAKE'
 MUJOCO_CMAKE_ARGS = 'MUJOCO_CMAKE_ARGS'
diff --git a/sample/CMakeLists.txt b/sample/CMakeLists.txt
index a29d2d4363..7e20cacb90 100644
--- a/sample/CMakeLists.txt
+++ b/sample/CMakeLists.txt
@@ -24,7 +24,7 @@ set(MSVC_INCREMENTAL_DEFAULT ON)
 
 project(
   mujoco_samples
-  VERSION 2.2.0
+  VERSION 2.2.1
   DESCRIPTION "MuJoCo samples binaries"
   HOMEPAGE_URL "https://mujoco.org"
 )
diff --git a/src/engine/engine_support.c b/src/engine/engine_support.c
index ea703d862f..dd1b7ddf10 100644
--- a/src/engine/engine_support.c
+++ b/src/engine/engine_support.c
@@ -35,8 +35,8 @@
   #endif
 #endif
 
-#define mjVERSION 220
-#define mjVERSIONSTRING "2.2.0"
+#define mjVERSION 221
+#define mjVERSIONSTRING "2.2.1"
 
 // names of disable flags
 const char* mjDISABLESTRING[mjNDISABLE] = {
diff --git a/test/engine/engine_support_test.cc b/test/engine/engine_support_test.cc
index 39f3e93774..4e9d57f2da 100644
--- a/test/engine/engine_support_test.cc
+++ b/test/engine/engine_support_test.cc
@@ -26,7 +26,7 @@ namespace {
 
 using VersionTest = MujocoTest;
 
-const char *const kExpectedVersionString = "2.2.0";
+const char *const kExpectedVersionString = "2.2.1";
 
 TEST_F(VersionTest, MjVersion) {
   EXPECT_EQ(mj_version(), mjVERSION_HEADER);
diff --git a/unity/Runtime/Bindings/MujocoBinaryRetriever.cs b/unity/Runtime/Bindings/MujocoBinaryRetriever.cs
index cc7ef2bd00..e4b4d84d0f 100644
--- a/unity/Runtime/Bindings/MujocoBinaryRetriever.cs
+++ b/unity/Runtime/Bindings/MujocoBinaryRetriever.cs
@@ -35,7 +35,7 @@ static void RegisteredPackagesEventHandler(
       if (AssetDatabase.LoadMainAssetAtPath(mujocoPath + "/mujoco.dylib") == null) {
         File.Copy(
             "/Applications/MuJoCo.app/Contents/Frameworks" +
-            "/mujoco.framework/Versions/Current/libmujoco.2.2.0.dylib",
+            "/mujoco.framework/Versions/Current/libmujoco.2.2.1.dylib",
             mujocoPath + "/mujoco.dylib");
         AssetDatabase.Refresh();
       }
@@ -43,7 +43,7 @@ static void RegisteredPackagesEventHandler(
       if (AssetDatabase.LoadMainAssetAtPath(mujocoPath + "/libmujoco.so") == null) {
         File.Copy(
             Environment.GetFolderPath(Environment.SpecialFolder.UserProfile) +
-            "/.mujoco/mujoco-2.2.0/lib/libmujoco.so.2.2.0",
+            "/.mujoco/mujoco-2.2.1/lib/libmujoco.so.2.2.1",
             mujocoPath + "/libmujoco.so");
         AssetDatabase.Refresh();
       }
diff --git a/unity/Runtime/Bindings/MujocoBindings.cs b/unity/Runtime/Bindings/MujocoBindings.cs
index f66597e8cb..c351a0f747 100644
--- a/unity/Runtime/Bindings/MujocoBindings.cs
+++ b/unity/Runtime/Bindings/MujocoBindings.cs
@@ -98,7 +98,7 @@ public static class MujocoLib {
 public const int mjMAXPLANEGRID = 200;
 public const bool THIRD_PARTY_MUJOCO_MJXMACRO_H_ = true;
 public const bool THIRD_PARTY_MUJOCO_MUJOCO_H_ = true;
-public const int mjVERSION_HEADER = 220;
+public const int mjVERSION_HEADER = 221;
 
 
 // ------------------------------------Enums------------------------------------
diff --git a/unity/package.json b/unity/package.json
index 16e67fa759..20deded3a7 100644
--- a/unity/package.json
+++ b/unity/package.json
@@ -1,7 +1,7 @@
 {
   "name": "org.mujoco",
   "displayName": "MuJoCo",
-  "version": "2.1.1",
+  "version": "2.2.1",
   "description": "MuJoCo importer and runtime plug-in",
   "dependencies": {},
   "author": {