diff --git a/pkgs/development/python-modules/srsly/default.nix b/pkgs/development/python-modules/srsly/default.nix
index 37b233574b20..92e6b84afdfe 100644
--- a/pkgs/development/python-modules/srsly/default.nix
+++ b/pkgs/development/python-modules/srsly/default.nix
@@ -3,6 +3,7 @@
 , buildPythonPackage
 , fetchPypi
 , pythonOlder
+, cython
 , mock
 , numpy
 , pathlib
@@ -19,6 +20,8 @@ buildPythonPackage rec {
     sha256 = "fa3c7375be8fe75f23c27feafbfb5f738d55ffdbf02964c6896fb7684f519a52";
   };
 
+  nativeBuildInputs = [ cython ];
+
   propagatedBuildInputs = lib.optional (pythonOlder "3.4") pathlib;
 
   checkInputs = [