diff --git a/metropolis/pkg/verity/encoder_test.go b/metropolis/pkg/verity/encoder_test.go
index db86cd6..116c6a4 100644
--- a/metropolis/pkg/verity/encoder_test.go
+++ b/metropolis/pkg/verity/encoder_test.go
@@ -70,7 +70,7 @@
 
 // Read implements io.Reader on devZeroReader, making it a source of zero
 // bytes.
-func (_ devZeroReader) Read(b []byte) (int, error) {
+func (devZeroReader) Read(b []byte) (int, error) {
 	for i := range b {
 		b[i] = 0
 	}