diff --git a/flake.nix b/flake.nix
index 278ea1c..49e9923 100644
--- a/flake.nix
+++ b/flake.nix
@@ -16,6 +16,7 @@
         default = pkgs.mkShell {
           buildInputs = with pkgs; [
             esphome
+            esptool
             cc2538-bsl
           ];