diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3873df901..01693e6f8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,8 @@
 
 - [fixed] Fixing error handling in FCM. The SDK now checks the key
   type.googleapis.com/google.firebase.fcm.v1.FcmError to set error code.
+- [fixed] Ensuring that `UserRecord.tokens_valid_after_time` always
+  returns an integer, and never returns `None`.
 
 # v2.13.0
 
diff --git a/firebase_admin/_user_mgt.py b/firebase_admin/_user_mgt.py
index d74e37715..10a6398f4 100644
--- a/firebase_admin/_user_mgt.py
+++ b/firebase_admin/_user_mgt.py
@@ -215,7 +215,7 @@ def tokens_valid_after_timestamp(self):
         valid_since = self._data.get('validSince')
         if valid_since is not None:
             return 1000 * int(valid_since)
-        return None
+        return 0
 
     @property
     def user_metadata(self):
diff --git a/tests/test_user_mgt.py b/tests/test_user_mgt.py
index 66e74cb73..d9c851eaf 100644
--- a/tests/test_user_mgt.py
+++ b/tests/test_user_mgt.py
@@ -151,6 +151,14 @@ def test_invalid_provider(self, data):
         with pytest.raises(ValueError):
             _user_mgt.ProviderUserInfo(data)
 
+    def test_tokens_valid_after_time(self):
+        user = auth.UserRecord({'localId' : 'user', 'validSince' : 100})
+        assert user.tokens_valid_after_timestamp == 100000
+
+    def test_no_tokens_valid_after_time(self):
+        user = auth.UserRecord({'localId' : 'user'})
+        assert user.tokens_valid_after_timestamp is 0
+
 
 class TestGetUser(object):