diff --git a/revid/revid_test.go b/revid/revid_test.go
index 006cd679..b8f9c1f7 100644
--- a/revid/revid_test.go
+++ b/revid/revid_test.go
@@ -92,7 +92,7 @@ func newTstFlvEncoder(dst io.Writer, fps int) (io.Writer, error) {
 	return &tstFlvEncoder{dst: dst}, nil
 }
 
-func (e *tstFlvEncoder) Write(d []byte) (int, error) { return 0, nil }
+func (e *tstFlvEncoder) Write(d []byte) (int, error) { return len(d), nil }
 
 // dummyMultiWriter emulates the MultiWriter provided by std lib, so that we
 // can access the destinations.