diff --git a/app/Main.hs b/app/Main.hs
index 0b2ccb7..d4551ce 100644
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -25,7 +25,6 @@ import           Data.IORef                               ( IORef
                                                           )
 import           Data.Time.Format                         ( defaultTimeLocale
                                                           , formatTime
-                                                          , iso8601DateFormat
                                                           )
 import           Lens.Micro.Platform                      ( set
                                                           , view
diff --git a/flake.nix b/flake.nix
index 18df29e..f27922b 100644
--- a/flake.nix
+++ b/flake.nix
@@ -10,7 +10,7 @@
 
   outputs = { self, nixpkgs, flake-utils }:
     let
-      ghcVer = "ghc810";
+      ghcVer = "ghc94";
       makeHaskellOverlay = overlay: final: prev: {
         haskell = prev.haskell // {
           packages = prev.haskell.packages // {
diff --git a/mat-chalmers.cabal b/mat-chalmers.cabal
index f59e97a..57691d6 100644
--- a/mat-chalmers.cabal
+++ b/mat-chalmers.cabal
@@ -32,11 +32,11 @@ library
                , attoparsec
                , base >=4.7
                , css-text
-               , exceptions == 0.10.4
+               , exceptions >= 0.10.4
                , heredoc == 0.2.0.0
                , http-client
                , http-client-tls >= 0.3.5.3
-               , logging-effect >= 1.3.12
+               , logging-effect >= 1.4.0
                , microlens-platform
                , lucid >= 2
                , mtl == 2.2.2
@@ -47,7 +47,8 @@ library
                , text >= 1.2.4.1
                , bytestring >= 0.10.12.0
                , file-embed
-               , thyme
+               , thyme >= 0.3.5.5
+               , time >= 1.9.3
                , word8 == 0.1.3
 
 executable mat-chalmers
diff --git a/stack.yaml b/stack.yaml
index bfa1c8b..3811a5b 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -1,8 +1,7 @@
-resolver: lts-18.28
+resolver: lts-21.12
 packages:
   - "."
 extra-deps:
   - wai-middleware-static-embedded-0.1.0.0@sha256:036b7823a5e69452d1fe1e270ef3d4988063caa5bb00b6dfc356e1c21b7433e3
-  - logging-effect-1.3.12@sha256:72d168dd09887649ba9501627219b6027cbec2d5541931555b7885b133785ce3,1679
 
 ghc-options: { "$locals": -ddump-to-file -ddump-hi }