diff --git a/credentials/apps/verifiable_credentials/composition/open_badges.py b/credentials/apps/verifiable_credentials/composition/open_badges.py
index 3ac84788a..82beffa85 100644
--- a/credentials/apps/verifiable_credentials/composition/open_badges.py
+++ b/credentials/apps/verifiable_credentials/composition/open_badges.py
@@ -18,7 +18,7 @@ class AchievementSchema(serializers.Serializer):  # pylint: disable=abstract-met
 
     TYPE = "Achievement"
 
-    id = serializers.CharField(source="user_credential.uuid")
+    id = serializers.UUIDField(source="user_credential.uuid", format="urn")
     type = serializers.CharField(default=TYPE)
     name = serializers.CharField(source="credential_name")
     description = serializers.CharField(source="credential_description")
diff --git a/credentials/apps/verifiable_credentials/composition/tests/test_open_badges.py b/credentials/apps/verifiable_credentials/composition/tests/test_open_badges.py
index 517c0e561..f575a739c 100644
--- a/credentials/apps/verifiable_credentials/composition/tests/test_open_badges.py
+++ b/credentials/apps/verifiable_credentials/composition/tests/test_open_badges.py
@@ -82,7 +82,7 @@ def test_credential_subject_achievement_id(self, program_issuance_line):
         """
         Credential Subject Achievement `id` property.
         """
-        expected_id = str(program_issuance_line.user_credential.uuid)
+        expected_id = f"urn:uuid:{program_issuance_line.user_credential.uuid}"
 
         composed_obv3 = OpenBadgesDataModel(program_issuance_line).data