diff --git a/pkgs/development/interpreters/python/cpython/default.nix b/pkgs/development/interpreters/python/cpython/default.nix
index 268f90f96166..5cb6d0a35f0d 100644
--- a/pkgs/development/interpreters/python/cpython/default.nix
+++ b/pkgs/development/interpreters/python/cpython/default.nix
@@ -342,7 +342,6 @@ in with passthru; stdenv.mkDerivation {
       substituteInPlace ./setup.py --replace $i /no-such-path
     done
   '' + optionalString stdenv.isDarwin ''
-    export NIX_CFLAGS_COMPILE="$NIX_CFLAGS_COMPILE -msse2"
     # Override the auto-detection in setup.py, which assumes a universal build
     export PYTHON_DECIMAL_WITH_MACHINE=${if stdenv.isAarch64 then "uint128" else "x64"}
   '' + optionalString (isPy3k && pythonOlder "3.7") ''