diff --git a/middleware/proxy.go b/middleware/proxy.go
index e220fd7..e6bf4c9 100644
--- a/middleware/proxy.go
+++ b/middleware/proxy.go
@@ -63,7 +63,7 @@ type (
 		Target       *url.URL
 		Rewrites     []string
 		Host         string
-		Transport    *http.Transport
+		Transport    http.RoundTripper
 		TargetPicker ProxyTargetPicker
 		Skipper      elton.Skipper
 	}