--- a/gameServer/CoreTypes.hs	Tue Jun 02 19:53:30 2015 +0100
+++ b/gameServer/CoreTypes.hs	Wed Jun 03 23:24:56 2015 +0300
@@ -38,7 +38,7 @@
 instance NFData B.ByteString
 #endif
 
-instance NFData (Chan a) where rnf a  = ()
+instance NFData (Chan a) where rnf a  = a `seq` ()
 
 instance NFData Action where
     rnf (AnswerClients chans msg) = chans `deepseq` msg `deepseq` ()

--- a/gameServer/EngineInteraction.hs	Tue Jun 02 19:53:30 2015 +0100
+++ b/gameServer/EngineInteraction.hs	Wed Jun 03 23:24:56 2015 +0300
@@ -16,9 +16,13 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  \-}
 
-{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE CPP, OverloadedStrings #-}
 
+#if defined(OFFICIAL_SERVER)
 module EngineInteraction(replayToDemo, checkNetCmd, toEngineMsg, drawnMapData) where
+#else
+module EngineInteraction(checkNetCmd, toEngineMsg, drawnMapData) where
+#endif
 
 import qualified Data.Set as Set
 import Control.Monad
@@ -89,6 +93,7 @@
         slotMessages = "\128\129\130\131\132\133\134\135\136\137\138"
         timedMessages = Set.fromList $ "+LlRrUuDdZzAaSjJ,NpPwtgfc12345" ++ slotMessages
 
+#if defined(OFFICIAL_SERVER)
 replayToDemo :: [TeamInfo]
         -> Map.Map B.ByteString B.ByteString
         -> Map.Map B.ByteString [B.ByteString]
@@ -152,6 +157,7 @@
                             ])
                         $ hedgehogs t
                         )
+#endif
 
 drawnMapData :: B.ByteString -> [B.ByteString]
 drawnMapData =