diff --git a/mupifDB/api/edm/dms3.py b/mupifDB/api/edm/dms3.py
index f3d10b1..c197053 100644
--- a/mupifDB/api/edm/dms3.py
+++ b/mupifDB/api/edm/dms3.py
@@ -1,5 +1,6 @@
 import pydantic 
-from typing import Literal,Optional,Union,Tuple,List,Set,Dict,Any,Self
+from typing import Literal,Optional,Union,Tuple,List,Set,Dict,Any
+from typing_extensions import Self # not in typing in Python<=3.10
 import json
 import typing
 import re
diff --git a/requirements.txt b/requirements.txt
index 2244ed4..fa0070c 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -31,6 +31,7 @@ pympler
 rotate-backups
 # XXX: this must be synchronized with mupif's requirements.txt
 pydantic>2.6
+typing_extensions
 oauthlib
 requests_oauthlib
 sphinxcontrib-openapi