diff --git a/pkgs/tools/security/knockpy/default.nix b/pkgs/tools/security/knockpy/default.nix
index 4a0bcde2b169..169165067c93 100644
--- a/pkgs/tools/security/knockpy/default.nix
+++ b/pkgs/tools/security/knockpy/default.nix
@@ -18,6 +18,7 @@ python3.pkgs.buildPythonApplication rec {
   pythonRelaxDeps = [
     "beautifulsoup4"
     "dnspython"
+    "pyopenssl"
     "tqdm"
   ];