diff --git a/pkg/storage/chunk/client/gcp/gcs_object_client.go b/pkg/storage/chunk/client/gcp/gcs_object_client.go
index d4b35e48d9df5..2e340c038e723 100644
--- a/pkg/storage/chunk/client/gcp/gcs_object_client.go
+++ b/pkg/storage/chunk/client/gcp/gcs_object_client.go
@@ -319,8 +319,7 @@ func gcsTransport(ctx context.Context, scope string, insecure bool, http2 bool,
 	transportOptions := []option.ClientOption{option.WithScopes(scope)}
 	if insecure {
 		customTransport.TLSClientConfig = &tls.Config{InsecureSkipVerify: true}
-		// When using `insecure` (testing only), we add a fake API key as well to skip credential chain lookups.
-		transportOptions = append(transportOptions, option.WithAPIKey("insecure"))
+		transportOptions = append(transportOptions, option.WithoutAuthentication())
 	}
 	if serviceAccount.String() != "" {
 		transportOptions = append(transportOptions, option.WithCredentialsJSON([]byte(serviceAccount.String())))