diff --git a/nix/configurations/vanadium/home/misc.nix b/nix/configurations/vanadium/home/misc.nix
index 33210803..7fc0c785 100644
--- a/nix/configurations/vanadium/home/misc.nix
+++ b/nix/configurations/vanadium/home/misc.nix
@@ -55,10 +55,15 @@
     type = "fcitx5";
   };
 
-  xdg.mimeApps = {
-    enable = true;
-    defaultApplications = {
-      "x-scheme-handler/mailto" = [ "org.gnome.Evolution.desktop" ];
+  xdg.mimeApps =
+    let
+      associations = {
+        "x-scheme-handler/mailto" = [ "org.gnome.Evolution.desktop" ];
+      };
+    in
+    {
+      enable = true;
+      associations.added = associations;
+      defaultApplications = associations;
     };
-  };
 }
diff --git a/nix/configurations/vanadium/home/programs.nix b/nix/configurations/vanadium/home/programs.nix
index f7030c31..a05cb216 100644
--- a/nix/configurations/vanadium/home/programs.nix
+++ b/nix/configurations/vanadium/home/programs.nix
@@ -102,6 +102,7 @@
     pkgs.mousai
     pkgs.localsend # file share with iOS
     pkgs.minder # mindmap tool
+    pkgs.mkvtoolnix
 
     # social
     pkgs.iamb
diff --git a/nix/homeModules/common/firefox.nix b/nix/homeModules/common/firefox.nix
index 556a528d..d479571b 100644
--- a/nix/homeModules/common/firefox.nix
+++ b/nix/homeModules/common/firefox.nix
@@ -129,15 +129,20 @@ in
     };
   };
 
-  xdg.mimeApps = lib.mkIf cfg.enable {
-    enable = true;
-    # source: https://unix.stackexchange.com/a/684582
-    defaultApplications = {
-      "text/html" = "firefox.desktop";
-      "x-scheme-handler/http" = "firefox.desktop";
-      "x-scheme-handler/https" = "firefox.desktop";
-      "x-scheme-handler/about" = "firefox.desktop";
-      "x-scheme-handler/unknown" = "firefox.desktop";
+  xdg.mimeApps =
+    let
+      # source: https://unix.stackexchange.com/a/684582
+      associations = {
+        "text/html" = "firefox.desktop";
+        "x-scheme-handler/http" = "firefox.desktop";
+        "x-scheme-handler/https" = "firefox.desktop";
+        "x-scheme-handler/about" = "firefox.desktop";
+        "x-scheme-handler/unknown" = "firefox.desktop";
+      };
+    in
+    lib.mkIf cfg.enable {
+      enable = true;
+      associations.added = associations;
+      defaultApplications = associations;
     };
-  };
 }
diff --git a/nix/homeModules/common/sioyek.nix b/nix/homeModules/common/sioyek.nix
index 6547d74d..93ee594d 100644
--- a/nix/homeModules/common/sioyek.nix
+++ b/nix/homeModules/common/sioyek.nix
@@ -3,6 +3,9 @@
   lib,
   ...
 }:
+let
+  cfg = config.programs.sioyek;
+in
 {
   programs.sioyek = {
     bindings = {
@@ -28,10 +31,15 @@
     config.should_launch_new_window = "1";
   };
 
-  xdg.mimeApps = lib.mkIf config.programs.sioyek.enable {
-    enable = true;
-    defaultApplications = {
-      "application/pdf" = [ "sioyek.desktop" ];
+  xdg.mimeApps =
+    let
+      associations = {
+        "application/pdf" = [ "sioyek.desktop" ];
+      };
+    in
+    lib.mkIf cfg.enable {
+      enable = true;
+      associations.added = associations;
+      defaultApplications = associations;
     };
-  };
 }