diff --git a/.github/workflows/diff.yml b/.github/workflows/diff.yml
index 0b1a60c126..9975e90316 100644
--- a/.github/workflows/diff.yml
+++ b/.github/workflows/diff.yml
@@ -37,11 +37,13 @@ jobs:
 
           # NOTE: We change the directory so binderhub the chart name won't be
           #       misunderstood as the local folder name.
+          # validation is disabled, because the config is for a different version!
           cd testing
 
           helm install binderhub-test binderhub \
               --values ./k8s-binder-k8s-hub/binderhub-chart-config.yaml \
               --repo https://jupyterhub.github.io/helm-chart/ \
+              --disable-openapi-validation \
               --version=$UPGRADE_FROM_VERSION
 
       - name: "Helm diff latest released dev chart with local chart"