diff --git a/pkgs/development/python-modules/numpy/1.16.nix b/pkgs/development/python-modules/numpy/1.16.nix
index ab4991cad145..1ab958a15f07 100644
--- a/pkgs/development/python-modules/numpy/1.16.nix
+++ b/pkgs/development/python-modules/numpy/1.16.nix
@@ -60,6 +60,7 @@ in buildPythonPackage rec {
   preConfigure = ''
     sed -i 's/-faltivec//' numpy/distutils/system_info.py
     export NPY_NUM_BUILD_JOBS=$NIX_BUILD_CORES
+    export OMP_NUM_THREADS=$((NIX_BUILD_CORES > 64 ? 64 : NIX_BUILD_CORES))
   '';
 
   preBuild = ''