diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index fc039385d..385d264ad 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -97,7 +97,7 @@ jobs:
           python -c "import openeye; assert openeye.oechem.OEChemIsLicensed(), 'oechem license check failed!'"
 
       - name: "Install GUFE from main@HEAD"
-        run: python -m pip install --no-deps git+https://github.com/OpenFreeEnergy/gufe@main
+        run: python -m pip install --no-deps git+https://github.com/OpenFreeEnergy/gufe@f8c49d59e756130a995d02dfe04d7a91acb1d791
 
       - name: "Install"
         run: python -m pip install --no-deps -e .
diff --git a/environment.yml b/environment.yml
index 259518f60..42741c0aa 100644
--- a/environment.yml
+++ b/environment.yml
@@ -44,4 +44,4 @@ dependencies:
   - pip:
     - sphinx-toolbox
     - openff-nagl-models>=0.1.2
-    - git+https://github.com/OpenFreeEnergy/gufe@main
+    - git+https://github.com/OpenFreeEnergy/gufe.git@f8c49d59e756130a995d02dfe04d7a91acb1d791