diff --git a/test_runner_test.go b/test_runner_test.go
index 0a0b0d69c..5c8461ad8 100644
--- a/test_runner_test.go
+++ b/test_runner_test.go
@@ -27,8 +27,7 @@ func TestTestRunner(t *testing.T) {
 		for key, value := range source.Inputs {
 			trie.Update(key, value)
 		}
-
-		if hex.EncodeToString([]byte(trie.Root)) != source.Expectation {
+		if hex.EncodeToString(trie.Root.([]byte)) != source.Expectation {
 			t.Error("trie root did not match")
 		}
 	})