diff --git a/backend/shell.nix b/backend/shell.nix
index a24dad2..7e83bc2 100644
--- a/backend/shell.nix
+++ b/backend/shell.nix
@@ -5,8 +5,6 @@ pkgs.mkShell {
     haskell-language-server
     stack
     stylish-haskell
-
-    libnotify
   ];
 
 }
diff --git a/backend/src/State/RoomsState.hs b/backend/src/State/RoomsState.hs
index f42eff1..af7e40b 100644
--- a/backend/src/State/RoomsState.hs
+++ b/backend/src/State/RoomsState.hs
@@ -62,7 +62,7 @@ roomStateDiffInOpenRooms newData = do
   current <- getRoomDataState
 
   let newRooms = filter roomNotEmpty $ filter (\newRoom -> isNothing $ find (sameName newRoom) current) newData
-  let oldRooms = filter roomNotEmpty $ filter (\oldRoom -> isNothing $ find (sameName oldRoom) newData) current
+  let oldRooms = filter (\newRoom -> isJust $ find (sameName newRoom) current) newData
 
   return (newRooms, oldRooms)
 
diff --git a/backend/stack.yaml b/backend/stack.yaml
index e142431..5383a0f 100644
--- a/backend/stack.yaml
+++ b/backend/stack.yaml
@@ -14,9 +14,8 @@
 # Use the latest resolver that uses the same ghc version
 # as build for nixos
 # this way we can use prebuild binaries for hls
-# go to
-# https://www.stackage.org/
-# and select the lts that is matching you hls version
+#resolver: nightly-2022-11-12
+#resolver: ghc-9.2.4
 resolver: lts-22.43
 #
 # The location of a snapshot can be provided as a file or url. Stack assumes