diff --git a/ckanext/scheming/plugins.py b/ckanext/scheming/plugins.py
index 0980a684..67c2e8fa 100644
--- a/ckanext/scheming/plugins.py
+++ b/ckanext/scheming/plugins.py
@@ -279,7 +279,7 @@ def composite_convert_to(key, data, errors, context):
                 del data[(f,)]
 
         if action_type == 'show':
-            if composite_convert_fields:
+            if composite_convert_fields and data_dict.get("extras"):
                 for ex in data_dict['extras']:
                     if ex['key'] in composite_convert_fields:
                         data_dict[ex['key']] = json.loads(ex['value'])