diff --git a/modules/home-manager/profiles/desktop.nix b/modules/home-manager/profiles/desktop.nix
index 72f011c3..cf139d72 100644
--- a/modules/home-manager/profiles/desktop.nix
+++ b/modules/home-manager/profiles/desktop.nix
@@ -121,6 +121,11 @@ in {
           quality-menu
         ];
       };
+
+      xdg.mimeApps.defaultApplications = {
+        "audio/*" = [ "mpv.desktop" ];
+        "video/*" = [ "mpv.desktop" ];
+      };
     })
 
     (lib.mkIf cfg.documents.enable {
@@ -132,6 +137,13 @@ in {
         vale # Elevate your fanfics to an arguably higher caliber!
       ];
 
+      xdg.mimeApps.defaultApplications = {
+        "application/pdf" = [
+          "sioyek.desktop"
+          "com.github.johnfactotum.Foliate.desktop"
+        ];
+      };
+
       # Some PDF viewer with a penchant for research.
       programs.sioyek = {
         enable = true;
diff --git a/modules/home-manager/profiles/editors.nix b/modules/home-manager/profiles/editors.nix
index aca0bdd0..42fc63d2 100644
--- a/modules/home-manager/profiles/editors.nix
+++ b/modules/home-manager/profiles/editors.nix
@@ -28,6 +28,11 @@ in {
           parinfer-rust
         ];
       };
+
+      xdg.mimeApps.defaultApplications = {
+        "application/json" = [ "nvim.desktop" ];
+        "text/plain" = [ "nvim.desktop" ];
+      };
     })
 
     # I only use Emacs for org-roam (seriously... I only learned Emacs for
@@ -79,6 +84,12 @@ in {
         sqlite
         anystyle-cli
       ];
+
+      xdg.mimeApps.defaultApplications = {
+        "application/json" = [ "emacs.desktop" ];
+        "text/org" = [ "emacs.desktop" ];
+        "text/plain" = [ "emacs.desktop" ];
+      };
     })
 
     # The Visual Studio Code setup. Probably the hardest one to fully configure
@@ -116,6 +127,11 @@ in {
         # Yay! Thank you!
         mutableExtensionsDir = true;
       };
+
+      xdg.mimeApps.defaultApplications = {
+        "application/json" = [ "code.desktop" ];
+        "text/plain" = [ "code.desktop" ];
+      };
     })
   ];
 }
diff --git a/modules/home-manager/profiles/research.nix b/modules/home-manager/profiles/research.nix
index 5843f843..0a6225c8 100644
--- a/modules/home-manager/profiles/research.nix
+++ b/modules/home-manager/profiles/research.nix
@@ -22,5 +22,9 @@ in {
     ];
 
     services.syncthing.enable = true;
+
+    xdg.mimeApps.defaultApplications = {
+      "application/vnd.anki" = [ "anki.desktop" ];
+    };
   };
 }