diff --git a/tape/dynamic_test.go b/tape/dynamic_test.go
index 81918f0..8e1e83c 100644
--- a/tape/dynamic_test.go
+++ b/tape/dynamic_test.go
@@ -166,10 +166,10 @@ func testEncodeAny(test *testing.T, value any, correctTag Tag, correctBytes tu.S
 	test.Log("got:    ", tu.HexBytes(bytes))
 	test.Log("correct:", correctBytes)
 	if tag != correctTag {
-		return fmt.Errorf("tag not equal")
+		return fmt.Errorf("tag not equal: %v != %v", tag, correctTag)
 	}
 	if ok, n := correctBytes.Check(bytes); !ok {
-		return fmt.Errorf("bytes not equal: %d", n)
+		return fmt.Errorf("bytes not equal at index %d", n)
 	}
 	if n != len(bytes) {
 		return fmt.Errorf("n not equal: %d != %d", n, len(bytes))