diff --git a/default.nix b/default.nix
index 006c8f9..310b008 100644
--- a/default.nix
+++ b/default.nix
@@ -30,10 +30,11 @@ 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}
   '';