diff --git a/overlays/reticulum.nix b/overlays/reticulum.nix
index 33a6b3a..0f21d11 100755
--- a/overlays/reticulum.nix
+++ b/overlays/reticulum.nix
@@ -12,10 +12,11 @@ in
         inherit version;
         sha256 = "554814231c237b9caacf8df669312e57dd7d3f84b6d4810125087d1a79a75d75";
       };
-      sourceRoot = "rns-${version}";
-      postUnpack = ''
-        echo "=== RNS source structure ==="
-        find . -maxdepth 3 -type d | head -20
+      patchPhase = ''
+        # Fix license_files syntax: ("LICENSE") is a string not tuple
+        # Newer setuptools iterates over it char by char, fails on 'S'
+        substituteInPlace setup.py \
+          --replace-fail 'license_files = ("LICENSE")' 'license_files = ("LICENSE",)'
       '';
       propagatedBuildInputs = with pyPkgs; [ cryptography pyserial ];
       doCheck = false;