diff --git a/ocaml-alcotest.spec b/ocaml-alcotest.spec
index 92a8574..0f3e731 100644
--- a/ocaml-alcotest.spec
+++ b/ocaml-alcotest.spec
@@ -83,7 +83,7 @@ find %{buildroot}%{_libdir}/ocaml -name \*.cmxs -exec chmod a+x {} \+
 %endif
 
 %check
-dune runtest -p alcotest
+dune runtest -j 1 -p alcotest
 
 %files
 %doc CHANGES.md README.md