diff --git a/pycsw/ogc/api/records.py b/pycsw/ogc/api/records.py
index f56fab573..49ea2c12a 100644
--- a/pycsw/ogc/api/records.py
+++ b/pycsw/ogc/api/records.py
@@ -1147,15 +1147,18 @@ def record2json(record, url, collection, mode='ogcapi-records'):
 
     # todo; for keywords with a scheme use the theme property
     if record.topicategory:
-        themes = [{
+        tctheme = {
             'concepts': [],
             'scheme': 'https://standards.iso.org/iso/19139/resources/gmxCodelists.xml#MD_TopicCategoryCode'
-        }]
-
-        for rtp in record.topicategory:
-            themes['concepts'].append({'id': rtp})
+        }
 
-        record_dict['properties']['themes'] = themes
+        if isinstance(record.topicategory, list):
+            for rtp in record.topicategory:
+                tctheme['concepts'].append({'id': rtp})
+        elif isinstance(record.topicategory, str):
+            tctheme['concepts'].append({'id': record.topicategory})
+        
+        record_dict['properties']['themes'] = [tctheme]
 
     if record.otherconstraints:
         if isinstance(record.otherconstraints, str) and record.otherconstraints not in [None, 'None']:
@@ -1226,15 +1229,15 @@ def record2json(record, url, collection, mode='ogcapi-records'):
         record_dict['properties']['contacts'] = rcnt
 
     if record.themes not in [None, '', 'null']:
-        ogcapi_themes = []
+        ogcapi_themes = record_dict['properties'].get('themes', []) 
         # For a scheme, prefer uri over label
         # OWSlib currently uses .keywords_object for keywords with url, see https://github.com/geopython/OWSLib/pull/765
         try:
             for theme in json.loads(record.themes):
                 try:
                     ogcapi_themes.append({
-                        'scheme': theme['thesaurus'].get('url', theme['thesaurus'].get('title', '')),
-                        'concepts': [{'id': c} for c in theme.get('keywords_object', []) if c not in [None, '']]
+                        'scheme': theme['thesaurus'].get('url') or theme['thesaurus'].get('title'),
+                        'concepts': [{'id': c.get('name','')} for c in theme.get('keywords', []) if 'name' in c and c['name'] not in [None, '']]
                     })
                 except Exception as err:
                     LOGGER.exception(f"failed to parse theme of {record.identifier}: {err}")
diff --git a/pycsw/ogc/api/templates/item.html b/pycsw/ogc/api/templates/item.html
index ce881aa63..cd08ec756 100644
--- a/pycsw/ogc/api/templates/item.html
+++ b/pycsw/ogc/api/templates/item.html
@@ -72,9 +72,9 @@ <h2>{{ data.get('properties',{}).get('title',data['id']) }}</h2>
                     {% for concept in theme['concepts'] %}
                       <li>
                         {% if concept['url'] %}
-                          <a href="{{ concept['url'] }}">{{ concept['name'] or concept['url'] }}</a>
+                          <a href="{{ concept['url'] }}">{{ concept['id'] or concept['url'] }}</a>
                         {% else %}
-                          {{ concept['name'] }}
+                          {{ concept['id'] }}
                         {% endif %}
                       </li>
                     {% endfor %}