diff --git a/pkgs/games/keen4/builder.sh b/pkgs/games/keen4/builder.sh
index c59308429611..571cd5a9c4bc 100644
--- a/pkgs/games/keen4/builder.sh
+++ b/pkgs/games/keen4/builder.sh
@@ -1,3 +1,4 @@
+#!/usr/bin/env bash
 
 # shellcheck source=/dev/null
 source "$stdenv"/setup