diff --git a/awx/api/serializers.py b/awx/api/serializers.py
index 02dc7796fd..1805f38352 100644
--- a/awx/api/serializers.py
+++ b/awx/api/serializers.py
@@ -343,7 +343,9 @@ class BaseSerializer(serializers.ModelSerializer):
                     continue
                 summary_fields[fk] = OrderedDict()
                 for field in related_fields:
-                    if field == 'credential_type_id' and fk == 'credential' and self.version < 2:  # TODO: remove version check in 3.3
+                    if (
+                            self.version < 2 and field == 'credential_type_id' and
+                            fk in ['credential', 'vault_credential']):  # TODO: remove version check in 3.3
                         continue
 
                     fval = getattr(fkval, field, None)