diff --git a/pkgs/development/python-modules/scikit-bio/default.nix b/pkgs/development/python-modules/scikit-bio/default.nix
index 1190d875005a..c909d8d66d08 100644
--- a/pkgs/development/python-modules/scikit-bio/default.nix
+++ b/pkgs/development/python-modules/scikit-bio/default.nix
@@ -62,6 +62,10 @@ buildPythonPackage (finalAttrs: {
     pytestCheckHook
   ];
 
+  preCheck = ''
+    export OMP_NUM_THREADS=1
+  '';
+
   # only the $out dir contains the built cython extensions, so we run the tests inside there
   enabledTestPaths = [ "${placeholder "out"}/${python.sitePackages}/skbio" ];