diff --git a/app/main.py b/app/main.py
index 7915e3b..cdae47c 100644
--- a/app/main.py
+++ b/app/main.py
@@ -82,10 +82,18 @@ async def inbox(
     payload = await request.json()
 
     if httpsig_checker:
-        await save_incoming(db_session, payload)
-        return Response(status_code=202)
+        if await save_incoming(db_session, payload):
+            return Response(status_code=202)
+        else:
+            return Response(
+                status_code=406,
+                content="invalid activitypub object"
+            )
     else:
-        return Response(status_code=406)
+        return Response(
+            status_code=406,
+            content="invalid http-sig"
+        )
 
 
 @app.post("/outbox")