diff --git a/default.nix b/default.nix
index 327db39..82aeb62 100644
--- a/default.nix
+++ b/default.nix
@@ -30,11 +30,10 @@ with pkgs; dockerTools.buildLayeredImage {
     cp "${./.}"/LICENSE .
     cp "${./.}"/*.py .
     cp -r "${./.}"/api .
+    cp -r "${./.}"/cython_lib .
     cp -r "${./.}"/middlewares .
     cp -r "${./.}"/models .
     cp -r "${./.}"/states .
-    mkdir cython_lib
-    cp "${./.}"/cython_lib/*.py cython_lib
     export PATH="${lib.makeBinPath shell.buildInputs}:$PATH"
     ${shell.shellHook}
   '';