diff --git a/imageproxy_test.go b/imageproxy_test.go
index 33267f8..771eb88 100644
--- a/imageproxy_test.go
+++ b/imageproxy_test.go
@@ -492,6 +492,7 @@ func TestTransformingTransport(t *testing.T) {
 	tr := &TransformingTransport{
 		Transport:     testTransport{},
 		CachingClient: client,
+		limiter:       make(chan struct{}, 1),
 	}
 	client.Transport = tr