diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
index 7ff37b62..30c0e95b 100644
--- a/.github/workflows/CI.yml
+++ b/.github/workflows/CI.yml
@@ -95,7 +95,7 @@ jobs:
         shell: bash -l {0}
         run: |
           # pytest -v --cov=openmmtools --cov-report=xml --color=yes openmmtools/tests/
-          nosetests openmmtools/tests --nocapture --verbosity=2 --with-timer --with-doctest -a '!slow'
+          nosetests openmmtools/tests --nocapture --cover-tests --with-coverage --cover-package=openmmtools --cover-xml --cover-xml-file=coverage.xml --verbosity=2 --with-timer --with-doctest -a '!slow'
 
       - name: CodeCov
         uses: codecov/codecov-action@v3
diff --git a/devtools/conda-envs/test_env.yaml b/devtools/conda-envs/test_env.yaml
index be26db4e..0de42d05 100644
--- a/devtools/conda-envs/test_env.yaml
+++ b/devtools/conda-envs/test_env.yaml
@@ -27,6 +27,7 @@ dependencies:
   - nose-timer
   - pytest
   - pytest-cov
+  - coverage
   
   # docs
   - numpydoc
diff --git a/docs/releasehistory.rst b/docs/releasehistory.rst
index 0f7eecbb..c646e784 100644
--- a/docs/releasehistory.rst
+++ b/docs/releasehistory.rst
@@ -1,6 +1,14 @@
 Release History
 ***************
 
+0.22.1 - Bugfix release
+=======================
+
+Bugfixes
+--------
+
+- Fixed issue where the error message thrown from openMM changed, so we need a case insensitive check. This was already fixed in most of the code base but one spot was missed. (PR `#684 <https://github.com/choderalab/openmmtools/pull/684>`_)
+
 0.22.0 - pymbar 4 support and gentle equilibration
 ==================================================
 
@@ -18,7 +26,7 @@ Bugfixes
 - Support for newer NetCDF versions (1.6 branch) by not using zlib compression for varying length variables. (PR `#654 <https://github.com/choderalab/openmmtools/pull/654>`_).
 
 0.21.5 - Bugfix release
-======================
+=======================
 
 Changed behaviors
 -----------------
@@ -131,7 +139,7 @@ Cleanup
 - Remove leftover `six` imports and `xrange` (`#504 <https://github.com/choderalab/openmmtools/pull/504>`_)
 
 0.20.1 - Bugfix release
-========================================
+=======================
 
 Enhancements
 ------------