diff --git a/testing/struct.go b/testing/struct.go
index c69023dcf..2ffb7ec01 100644
--- a/testing/struct.go
+++ b/testing/struct.go
@@ -17,7 +17,7 @@ import (
 //
 // CompareValues expects the two values to be of the same underlying type.
 // Doing otherwise will result in undefined behavior.
-func CompareValues(expect, actual interface{}) error {
+func CompareValues(expect, actual interface{}, _ ...interface{}) error {
 	return deepEqual(reflect.ValueOf(expect), reflect.ValueOf(actual), "<root>")
 }