diff --git a/flake.lock b/flake.lock
index 2e51345..fdee9b3 100644
--- a/flake.lock
+++ b/flake.lock
@@ -49,6 +49,22 @@
         "type": "github"
       }
     },
+    "crdt": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1613110836,
+        "narHash": "sha256-i37FEsWPFgowMogUFwdu2iOBXS3rvNFh7w8cEhyERkk=",
+        "ref": "master",
+        "rev": "3a2424afa91e2205a18af68972537df8695e7c06",
+        "revCount": 69,
+        "type": "git",
+        "url": "https://code.librehq.com/qhong/crdt.el"
+      },
+      "original": {
+        "type": "git",
+        "url": "https://code.librehq.com/qhong/crdt.el"
+      }
+    },
     "deploy-rs": {
       "inputs": {
         "flake-compat": "flake-compat",
@@ -399,6 +415,7 @@
       "inputs": {
         "NUR": "NUR",
         "base16-unclaimed-schemes": "base16-unclaimed-schemes",
+        "crdt": "crdt",
         "deploy-rs": "deploy-rs",
         "emacs-overlay": "emacs-overlay",
         "flake-compat": "flake-compat_2",
diff --git a/flake.nix b/flake.nix
index f5030f7..e5320e3 100644
--- a/flake.nix
+++ b/flake.nix
@@ -59,6 +59,10 @@
       url = "github:AlexxIT/SonoffLAN";
       flake = false;
     };
+    crdt = {
+      url = "git+https://code.librehq.com/qhong/crdt.el";
+      flake = false;
+    };
   };
 
   outputs = { nixpkgs, nix, self, deploy-rs, ... }@inputs: {
diff --git a/modules/applications/emacs/default.nix b/modules/applications/emacs/default.nix
index bac3e72..4fe822c 100644
--- a/modules/applications/emacs/default.nix
+++ b/modules/applications/emacs/default.nix
@@ -1,4 +1,16 @@
-{ pkgs, config, lib, ... }: {
+{ pkgs, config, lib, inputs, ... }:
+let
+  emacs = pkgs.emacsPgtk;
+  crdt = (pkgs.emacsPackagesNgFor emacs).trivialBuild {
+    pname = "crdt";
+    version = "0.0.0";
+    phases = [ "buildPhase" "installPhase" ];
+    buildPhase = ''
+      cp ${inputs.crdt}/*.el .
+    '';
+  };
+in
+{
   # secrets-envsubst.emacs = {
     # owner = "balsoft:users";
     # directory = "emacs";
@@ -7,7 +19,7 @@
   home-manager.users.balsoft = {
     programs.emacs = {
       enable = true;
-      package = pkgs.emacsPgtk;
+      package = emacs;
       extraPackages = epkgs:
         with epkgs; [
           use-package
@@ -57,6 +69,7 @@
           org-caldav
           envrc
           lsp-haskell
+          crdt
         ];
     };
 
diff --git a/modules/applications/emacs/init.el b/modules/applications/emacs/init.el
index 6a5e704..db9dc95 100755
--- a/modules/applications/emacs/init.el
+++ b/modules/applications/emacs/init.el
@@ -240,5 +240,7 @@ If point was already at that position, move point to beginning of line."
   (envrc-global-mode)
   (advice-add 'lsp :before (lambda (&optional n) (envrc--update))))
 
+(use-package crdt)
+
 (load-theme 'manoj-dark t)
 ;;; init.el ends here