diff --git a/hack/update-generated.sh b/hack/update-generated.sh
index 4e250b6bdc75..09a23b064ce6 100755
--- a/hack/update-generated.sh
+++ b/hack/update-generated.sh
@@ -13,8 +13,10 @@ ENABLE_STORAGE_GCE_PD_DRIVER=yes go generate -mod vendor ./test/extended
 go run -mod vendor ./cmd/openshift-tests render test-report --output-dir=./zz_generated.manifests
 
 # Update mirror mapping from upstream to quay
+# By default, "openshift-tests images" lists images from external binaries. However, we force
+# this scriptto list images from built-in tests in order to avoid requiring an OCP cluster.
 echo "# This file is generated by hack/update-generated.sh" > test/extended/util/image/zz_generated.txt
-go run -mod vendor ./cmd/openshift-tests images --upstream --to-repository quay.io/openshift/community-e2e-images >> test/extended/util/image/zz_generated.txt
+OPENSHIFT_SKIP_EXTERNAL_TESTS=1 go run -mod vendor ./cmd/openshift-tests images --upstream --to-repository quay.io/openshift/community-e2e-images >> test/extended/util/image/zz_generated.txt
 
 os::build::setup_env