diff --git a/sat/tools/common/template.py b/sat/tools/common/template.py
index 3bd07003..6790a350 100644
--- a/sat/tools/common/template.py
+++ b/sat/tools/common/template.py
@@ -451,6 +451,11 @@ class Renderer(object):
 
         # policies
         self.env.policies["ext.i18n.trimmed"] = True
+        self.env.policies["json.dumps_kwargs"] = {
+            "sort_keys": True,
+            # if object can't be serialised, we use None
+            "default": lambda o: o.json() if hasattr(o, "json") else None
+        }
 
     def getFrontURL(self, template_data, path=None):
         """Give front URL (i.e. URL seen by end-user) of a path