diff --git a/wavinfo/__main__.py b/wavinfo/__main__.py
index 82a0dbf..3e5ad9f 100644
--- a/wavinfo/__main__.py
+++ b/wavinfo/__main__.py
@@ -9,7 +9,7 @@
 from base64 import b64encode
 from cmd import Cmd
 from shlex import split
-from typing import List, Dict
+from typing import List, Dict, Union
 
 
 class MyJSONEncoder(json.JSONEncoder):
@@ -29,7 +29,7 @@ class MissingDataError(RuntimeError):
 class MetaBrowser(Cmd):
     prompt = "(wavinfo) "
 
-    metadata: List | Dict
+    metadata: Union[List, Dict]
     path: List[str] = []
 
     @property