diff --git a/proxywriter_test.go b/proxywriter_test.go
index 6089d68..b57357f 100644
--- a/proxywriter_test.go
+++ b/proxywriter_test.go
@@ -86,7 +86,7 @@
 }
 
 type dumbReader struct {
-	r *strings.Reader
+	r io.Reader
 }
 
 func (r dumbReader) Read(p []byte) (int, error) {