diff --git a/CHANGELOG.md b/CHANGELOG.md
index ba897d5247..79dad02a8e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,10 +6,8 @@ request related to the change, then we may provide the commit.
 
 This is not a comprehensive list of changes but rather a hand-curated collection of the more notable ones. For a comprehensive history, see the [OpenSim Core GitHub repo](https://github.com/opensim-org/opensim-core).
 
-**Note**: This document is currently under construction.
-
-v4.0 (in development)
-=====================
+v4.0
+====
 
 Converting from v3.x to v4.0
 -----------------------------
@@ -243,17 +241,13 @@ programmatically in MATLAB or python.
 - The source code for the "From the Ground Up: Building a Passive Dynamic
   Walker Example" was added to this repository.
 - OpenSim no longer looks for the simbody-visualizer using the environment
-  variable `OPENSIM_HOME`.
+  variable `OPENSIM_HOME`. OpenSim uses `PATH` instead.
+- The Thelen2003Muscle now depend on separate components for modeling pennation,
+  and activation dynamics.
 
 Documentation
---------------
+-------------
 - Improved Doxygen layout and fixed several bugs and warnings (various)
 - All mentions of SimTK/Simbody classes in OpenSim's Doxygen now provide links directly to SimTK/Simbody's doxygen.
 - Added a detailed README.md wtith build instructions, as well as guides to contributing and developing (CONTRIBUTING.md).
 - Included GIFs in Doxygen for several commonly used Joint types
-
-STILL NEED TO ADD:
-- Additional changes to Model Component Interface, Iterator (any PRs labeled "New MCI")
-- PR #364
-- PR #370
-- PR #378
diff --git a/OpenSim/Common/XMLDocument.cpp b/OpenSim/Common/XMLDocument.cpp
index d3c1bb8d37..20a82597bb 100644
--- a/OpenSim/Common/XMLDocument.cpp
+++ b/OpenSim/Common/XMLDocument.cpp
@@ -65,7 +65,8 @@ using namespace std;
 // 30515 for WrapObject color, display_preference, VisibleObject -> Appearance
 // 30516 for GeometryPath default_color -> Appearance
 // 30517 for removal of _connectee_name suffix to shorten XML for socket, input
-const int XMLDocument::LatestVersion = 30517;
+// 40000 for OpenSim 4.0 release
+const int XMLDocument::LatestVersion = 40000;
 //=============================================================================
 // DESTRUCTOR AND CONSTRUCTOR(S)
 //=============================================================================