diff --git a/actions/setup/action.yml b/actions/setup/action.yml
index 851f4af7c..b0301c121 100644
--- a/actions/setup/action.yml
+++ b/actions/setup/action.yml
@@ -32,6 +32,8 @@ inputs:
     default: "."
   knative-version:
     description: 'Version of Knative to install (1.1.0, 1.1.1, etc.)'
+    required: true
+    default: '1.10.5'
   registry-name:
     description: 'Name of the registry to install (registry.local)'
     required: true
@@ -93,7 +95,8 @@ runs:
         ./setup-kind.sh \
           --registry-url ${{ inputs.registry-name }}:${{ inputs.registry-port }} \
           --cluster-suffix ${{ inputs.cluster-suffix }} \
-          --k8s-version ${{ inputs.k8s-version }} ${{ inputs.knative-version && join('--knative-version ',inputs.knative-version) }}
+          --k8s-version ${{ inputs.k8s-version }} \
+          --knative-version ${{ inputs.knative-version }}
       fi
 
       echo "Installing sigstore scaffolding @ ${tag}"