diff --git a/SAS/TMSS/src/tmss/tmssapp/serializers/specification.py b/SAS/TMSS/src/tmss/tmssapp/serializers/specification.py
index 7ac24b865eca008a90ab54c0d72582144e1194b8..493f8ea456bffdfee3a7a25c29e7ffead7788c2a 100644
--- a/SAS/TMSS/src/tmss/tmssapp/serializers/specification.py
+++ b/SAS/TMSS/src/tmss/tmssapp/serializers/specification.py
@@ -153,13 +153,13 @@ class DatatypeSerializer(serializers.ModelSerializer):
         fields = '__all__'
 
 
-class DataformatSerializer(serializers.ModelSerializer):
+class DataformatSerializer(RelationalHyperlinkedModelSerializer):
     class Meta:
         model = models.Dataformat
         fields = '__all__'
 
 
-class CopyReasonSerializer(serializers.ModelSerializer):
+class CopyReasonSerializer(RelationalHyperlinkedModelSerializer):
     class Meta:
         model = models.CopyReason
         fields = '__all__'
@@ -201,25 +201,25 @@ class ResourceTypeSerializer(RelationalHyperlinkedModelSerializer):
         extra_fields = ['name']
 
 
-class FlagSerializer(serializers.ModelSerializer):
+class FlagSerializer(RelationalHyperlinkedModelSerializer):
     class Meta:
         model = models.Flag
         fields = '__all__'
 
 
-class SettingSerializer(serializers.ModelSerializer):
+class SettingSerializer(RelationalHyperlinkedModelSerializer):
     class Meta:
         model = models.Setting
         fields = '__all__'
 
 
-class ProjectCategorySerializer(serializers.ModelSerializer):
+class ProjectCategorySerializer(RelationalHyperlinkedModelSerializer):
     class Meta:
         model = models.ProjectCategory
         fields = '__all__'
 
 
-class PeriodCategorySerializer(serializers.ModelSerializer):
+class PeriodCategorySerializer(RelationalHyperlinkedModelSerializer):
     class Meta:
         model = models.PeriodCategory
         fields = '__all__'