diff --git a/invenio_rdm_records/records/api.py b/invenio_rdm_records/records/api.py
index 377ef6c82..83180c770 100644
--- a/invenio_rdm_records/records/api.py
+++ b/invenio_rdm_records/records/api.py
@@ -184,7 +184,7 @@ class CommonFieldsMixin:
         ),
         subjects=PIDListRelation(
             "metadata.subjects",
-            keys=["subject", "scheme", "props"],
+            keys=["subject", "scheme", "props", "identifiers"],
             pid_field=Subject.pid,
             cache_key="subjects",
         ),
diff --git a/invenio_rdm_records/resources/serializers/datacite/schema.py b/invenio_rdm_records/resources/serializers/datacite/schema.py
index 82d685e41..41af4300f 100644
--- a/invenio_rdm_records/resources/serializers/datacite/schema.py
+++ b/invenio_rdm_records/resources/serializers/datacite/schema.py
@@ -538,14 +538,20 @@ def get_subjects(self, obj):
         for subject in subjects:
             entry = {"subject": subject.get("subject")}
 
-            id_ = subject.get("id")
-            if id_:
-                entry["subjectScheme"] = subject.get("scheme")
-                try:
-                    validator(id_)
-                    entry["valueURI"] = id_
-                except ValidationError:
-                    pass
+            subject_scheme = subject.get("scheme")
+            if subject_scheme:
+                entry["subjectScheme"] = subject_scheme
+
+            # Get identifiers and assign valueURI if scheme is 'url'
+            identifiers = subject.get("identifiers", [])
+            for identifier in identifiers:
+                if identifier.get("scheme") == "url":
+                    entry["valueURI"] = identifier.get("identifier")
+                    break
+
+            # Add id as valueURI if no 'url' scheme is found
+            if "valueURI" not in entry and subject.get("id"):
+                entry["valueURI"] = subject.get("id")
 
             serialized_subjects.append(entry)