diff --git a/src/Vervis/Foundation.hs b/src/Vervis/Foundation.hs
index c806ece..5b795ff 100644
--- a/src/Vervis/Foundation.hs
+++ b/src/Vervis/Foundation.hs
@@ -654,7 +654,7 @@ instance YesodRemoteActorStore App where
 
 instance YesodActivityPub App where
     sitePostSignedHeaders _ =
-        hRequestTarget :| [hHost, hDate, hActivityPubActor]
+        hRequestTarget :| [hHost, hDate, hDigest, hActivityPubActor]
     siteGetHttpSign = do
         (akey1, akey2, new1) <- liftIO . readTVarIO =<< asksSite appActorKeys
         renderUrl <- askUrlRender