diff --git a/flake.nix b/flake.nix
index 7e0764b..d00bff0 100644
--- a/flake.nix
+++ b/flake.nix
@@ -43,7 +43,7 @@
           buildInputs = with pkgs; [udev libudev-zero];
           postInstall = ''
             mkdir -p $out/etc/udev/rules.d
-            echo "${udev-rule}" > $out/etc/udev/rules.d/70-heliox.rules
+            echo '${udev-rule}' > $out/etc/udev/rules.d/70-heliox.rules
           '';
         };