diff --git a/tape/dynamic.go b/tape/dynamic.go
index c0e5301..4c03dae 100644
--- a/tape/dynamic.go
+++ b/tape/dynamic.go
@@ -156,8 +156,10 @@ func decodeAny(decoder *Decoder, destination reflect.Value, tag Tag) (n int, err
 			n += nn; if err != nil { return n, err }
 			table.SetMapIndex(reflect.ValueOf(key), value)
 		}
+	default:
+		return n, fmt.Errorf("unknown TN %d", tag.TN())
 	}
-	return n, fmt.Errorf("unknown TN %d", tag.TN())
+	return n, nil
 }
 
 // TagAny returns the correct tag for an "any" value. Returns an error if the