diff --git a/pkgs/development/python-modules/pydantic/default.nix b/pkgs/development/python-modules/pydantic/default.nix
index 93af15c4e0d9..1a038fe7de8c 100644
--- a/pkgs/development/python-modules/pydantic/default.nix
+++ b/pkgs/development/python-modules/pydantic/default.nix
@@ -26,6 +26,7 @@
 , ujson
 , orjson
 , hypothesis
+, libxcrypt
 }:
 
 buildPythonPackage rec {
@@ -51,6 +52,10 @@ buildPythonPackage rec {
     sed -i '/flake8/ d' Makefile
   '';
 
+  buildInputs = lib.optionals (pythonOlder "3.9") [
+    libxcrypt
+  ];
+
   nativeBuildInputs = [
     cython
   ] ++ lib.optionals withDocs [