diff --git a/pkgs/by-name/ka/karlender/package.nix b/pkgs/by-name/ka/karlender/package.nix
index 7c3b1aad45056..eedb90c44fac2 100644
--- a/pkgs/by-name/ka/karlender/package.nix
+++ b/pkgs/by-name/ka/karlender/package.nix
@@ -9,42 +9,67 @@
   glib,
   tzdata,
   nix-update-script,
+  dbus,
+  cargo-gra,
+  fetchpatch,
 }:
 
 rustPlatform.buildRustPackage rec {
   pname = "karlender";
-  version = "0.9.2";
+  version = "0.10.4";
 
   src = fetchFromGitLab {
     owner = "floers";
     repo = pname;
     rev = "v${version}";
-    hash = "sha256-txPMOWwxgs9PH1Scnwr/X4cuMIUa+eoLW3K2aqmqRMQ=";
+    hash = "sha256-W+s1RCPwy7ZiK514AaQLwV9y+VJ58oMGlrS5cdoFKIg=";
   };
 
-  cargoHash = "sha256-OyyzzkoYBed2XFCesj3QBodT9e/BaapGl/z0f6+cDZA=";
+  cargoPatches = [
+    # https://gitlab.com/floers/calendar-stuff/karlender/-/merge_requests/43
+    # Remove it when it is merged and released.
+    (fetchpatch {
+      url = "https://gitlab.com/floers/calendar-stuff/karlender/-/commit/ce50c68323a834a0ee2cbff88ed285a971dfd91e.patch";
+      hash = "sha256-0hGgJPwnSNGTO/eiooQkQlBJ4brbaWVKRY6MT1PZApg=";
+    })
+    (fetchpatch {
+      url = "https://gitlab.com/floers/calendar-stuff/karlender/-/commit/98282a07aa92adeadeb5cff4fae2f32b73468357.patch";
+      hash = "sha256-nfbFdRYGmBzhaNwqwc8qXE9zCScT4Ra9bAth3i0q+qM=";
+    })
+  ];
+
+  cargoHash = "sha256-CeHIx6oUtAcr6tBdqmIDTLuYcesaA6G72L3HwHDLY7Y=";
 
   nativeBuildInputs = [
     pkg-config
     wrapGAppsHook4
     glib
+    cargo-gra
   ];
 
   buildInputs = [
     gtk4
     libadwaita
+    dbus
+  ];
+
+  checkFlags = [
+    "--skip domain::time::tests::test_get_correct_offset_for_dst" # Need time
   ];
 
+  preBuild = ''
+    cargo-gra gen
+  '';
+
   postPatch = ''
-    substituteInPlace src/domain/time.rs --replace "/usr/share/zoneinfo" "${tzdata}/share/zoneinfo"
-    substituteInPlace build.rs --replace "// gra::build" "gra::build"
+    substituteInPlace src/domain/time.rs --replace-fail "/usr/share/zoneinfo" "${tzdata}/share/zoneinfo"
   '';
 
   postInstall = ''
     substituteInPlace target/gra-gen/data/codes.loers.Karlender.desktop \
-      --replace "Exec=codes.loers.Karlender" "Exec=karlender"
+      --replace-fail "Exec=codes.loers.Karlender" "Exec=karlender"
     substituteInPlace target/gra-gen/data/codes.loers.Karlender.appdata.xml \
-      --replace "<binary>codes.loers.Karlender</binary>" "<binary>karlender</binary>"
+      --replace-fail "<binary>codes.loers.Karlender</binary>" "<binary>karlender</binary>"
     install -Dm444 target/gra-gen/codes.loers.Karlender.gschema.xml -t $out/share/gsettings-schemas/$name/glib-2.0/schemas/
     glib-compile-schemas $out/share/gsettings-schemas/$name/glib-2.0/schemas/
     install -Dm444 target/gra-gen/data/codes.loers.Karlender.svg -t $out/share/icons/hicolor/scalable/apps/