fix test
diff --git a/warnings_test.go b/warnings_test.go
index 8d6ad0d..b4a6ea4 100644
--- a/warnings_test.go
+++ b/warnings_test.go
@@ -8,7 +8,7 @@
 	w "gopkg.in/warnings.v0"
 )
 
-var _ error = List{}
+var _ error = w.List{}
 
 type warn string