diff --git a/avers-server.cabal b/avers-server.cabal
--- a/avers-server.cabal
+++ b/avers-server.cabal
@@ -1,5 +1,5 @@
 name:                avers-server
-version:             0.0.4
+version:             0.0.5
 synopsis:            Server implementation of the Avers API
 description:         See README.md
 homepage:            http://github.com/wereHamster/avers-server
diff --git a/src/Avers/Server/Instances.hs b/src/Avers/Server/Instances.hs
--- a/src/Avers/Server/Instances.hs
+++ b/src/Avers/Server/Instances.hs
@@ -34,17 +34,18 @@
     type ServerT (Credentials :> sublayout) m =
         Credentials -> ServerT sublayout m
 
-    route Proxy context subserver = WithRequest $ \request ->
-        route (Proxy :: Proxy sublayout) context (addCapture subserver $ do
+    route Proxy context subserver =
+        route (Proxy :: Proxy sublayout) context (addAuthCheck subserver authCheck)
+      where
+        authCheck = withRequest $ \request -> do
             let mbCookieHeaders = lookup "cookie" (requestHeaders request)
                 mbSessionIdText = lookup "session" =<< fmap parseCookiesText mbCookieHeaders
 
-            pure $ case mbSessionIdText of
-                Nothing -> FailFatal err401
+            case mbSessionIdText of
+                Nothing -> delayedFailFatal err401
                 Just sessionIdText -> case parseQueryParam sessionIdText of
-                    Left _ -> FailFatal err401
-                    Right sId -> Route $ (SessionIdCredential $ SessionId sId)
-        )
+                    Left _ -> delayedFailFatal err401
+                    Right sId -> pure $ SessionIdCredential $ SessionId sId
 
 
 
@@ -53,17 +54,18 @@
     type ServerT (SessionId :> sublayout) m =
         SessionId -> ServerT sublayout m
 
-    route Proxy context subserver = WithRequest $ \request ->
-        route (Proxy :: Proxy sublayout) context (addCapture subserver $ do
+    route Proxy context subserver =
+        route (Proxy :: Proxy sublayout) context (addAuthCheck subserver authCheck)
+      where
+        authCheck = withRequest $ \request -> do
             let mbCookieHeaders = lookup "cookie" (requestHeaders request)
                 mbSessionIdText = lookup "session" =<< fmap parseCookiesText mbCookieHeaders
 
-            pure $ case mbSessionIdText of
-                Nothing -> FailFatal err401
+            case mbSessionIdText of
+                Nothing -> delayedFailFatal err401
                 Just sessionIdText -> case parseQueryParam sessionIdText of
-                    Left _ -> FailFatal err401
-                    Right sId -> Route $ SessionId sId
-        )
+                    Left _ -> delayedFailFatal err401
+                    Right sId -> pure $ SessionId sId
 
 
 instance ToByteString SetCookie where