diff --git a/default.nix b/default.nix
index 17a2804..bbfd3e6 100644
--- a/default.nix
+++ b/default.nix
@@ -4,9 +4,10 @@ in
 pkgs.mkShell {
   packages = with pkgs; [
     # Choose the build tools that you need
+    cmake
     gcc
     gdb
-    cmake
+    valgrind
   ];
 }