diff --git a/pkgs/by-name/os/ospd-openvas/package.nix b/pkgs/by-name/os/ospd-openvas/package.nix
index c4017f2e521e..0900aa4a1250 100644
--- a/pkgs/by-name/os/ospd-openvas/package.nix
+++ b/pkgs/by-name/os/ospd-openvas/package.nix
@@ -18,6 +18,7 @@ python3.pkgs.buildPythonApplication rec {
 
   pythonRelaxDeps = [
     "defusedxml"
+    "lxml"
     "packaging"
     "psutil"
     "python-gnupg"