diff --git a/.github/workflows/non-omv.yml b/.github/workflows/non-omv.yml
index 5c66510..f9eb4fe 100644
--- a/.github/workflows/non-omv.yml
+++ b/.github/workflows/non-omv.yml
@@ -27,6 +27,8 @@ jobs:
       run: |
         pip install git+https://github.com/OpenSourceBrain/osb-model-validation
         pip install scipy sympy matplotlib cython pandas tables
+        
+        pip install 'numpy<=1.23.0' # see https://github.com/OpenSourceBrain/osb-model-validation/issues/91
 
     - name: Regenerate and test
       run: |
diff --git a/.github/workflows/omv-ci.yml b/.github/workflows/omv-ci.yml
index 8686b82..e9b997a 100644
--- a/.github/workflows/omv-ci.yml
+++ b/.github/workflows/omv-ci.yml
@@ -26,6 +26,9 @@ jobs:
       run: |
         pip install git+https://github.com/OpenSourceBrain/osb-model-validation
         pip install scipy sympy matplotlib cython pandas tables
+
+        pip install 'numpy<=1.23.0' # see https://github.com/OpenSourceBrain/osb-model-validation/issues/91
+
     - name: Run OMV tests on engine ${{ matrix.engine }}
       run: |
         omv all -V --engine=${{ matrix.engine }}