diff --git a/hbs2-core/lib/HBS2/Net/Proto/Types.hs b/hbs2-core/lib/HBS2/Net/Proto/Types.hs
index 3ee44ed4..75f61644 100644
--- a/hbs2-core/lib/HBS2/Net/Proto/Types.hs
+++ b/hbs2-core/lib/HBS2/Net/Proto/Types.hs
@@ -17,7 +17,7 @@ class (Hashable (Peer e), Eq (Peer e)) => HasPeer e where
   data family (Peer e) :: Type
 
 
-class MonadIO m => Response e p (m :: Type -> Type) | p -> e where
+class (MonadIO m, HasProtocol e p) => Response e p m | p -> e where
   response :: p -> m ()
   deferred :: Proxy p -> m () -> m ()
 
diff --git a/hbs2-tests/test/Main.hs b/hbs2-tests/test/Main.hs
index 7ccf377a..e4f08a6b 100644
--- a/hbs2-tests/test/Main.hs
+++ b/hbs2-tests/test/Main.hs
@@ -61,7 +61,6 @@ instance HasProtocol Fake (BlockSize Fake) where
 
 blockSizeHandler :: forall e m s . ( MonadIO m
                                    , Response e (BlockSize e) m
-                                   , HasProtocol e (BlockSize e)
                                    , s ~ SimpleStorage HbSync
                                    )
                 => s