diff --git a/tools/emacs/default.nix b/tools/emacs/default.nix
index e29f2f05f..6aab4537e 100644
--- a/tools/emacs/default.nix
+++ b/tools/emacs/default.nix
@@ -49,6 +49,7 @@ let
     browse-kill-ring
     cargo
     clojure-mode
+    cmake-mode
     counsel
     counsel-notmuch
     dash-functional