diff --git a/events/handlers/ap_delivery_handler.py b/events/handlers/ap_delivery_handler.py
index 7dbf9ad..001b9ce 100644
--- a/events/handlers/ap_delivery_handler.py
+++ b/events/handlers/ap_delivery_handler.py
@@ -39,7 +39,10 @@ def _build_activity_json(activity: APActivity, actor: ActorProfile, domain: str)
         obj.setdefault("published", activity.published.isoformat() if activity.published else None)
 
     return {
-        "@context": "https://www.w3.org/ns/activitystreams",
+        "@context": [
+            "https://www.w3.org/ns/activitystreams",
+            "https://w3id.org/security/v1",
+        ],
         "id": activity.activity_id,
         "type": activity.activity_type,
         "actor": actor_url,
diff --git a/services/federation_impl.py b/services/federation_impl.py
index 0ad5728..67767c1 100644
--- a/services/federation_impl.py
+++ b/services/federation_impl.py
@@ -163,7 +163,10 @@ class SqlFederationService:
             from shared.utils.ipfs_client import add_json, is_available
             if await is_available():
                 activity_json = {
-                    "@context": "https://www.w3.org/ns/activitystreams",
+                    "@context": [
+                        "https://www.w3.org/ns/activitystreams",
+                        "https://w3id.org/security/v1",
+                    ],
                     "id": activity_uri,
                     "type": activity_type,
                     "actor": f"https://{domain}/users/{username}",