diff --git a/coreutils.spec b/coreutils.spec
index 079cc3b..42b365b 100644
--- a/coreutils.spec
+++ b/coreutils.spec
@@ -193,7 +193,7 @@ ln -v lib/parse-datetime.{c,y} .
   chmod a+x tests/misc/sort-mb-tests.sh
   # Avoid parallel make, because otherwise some timeout based tests like
   # rm/ext3-perf may fail due to high CPU or IO load.
-  %make_build check-very-expensive VERBOSE=yes \
+  %make_build -j1 check-very-expensive VERBOSE=yes \
     && install -d -m 755 %{buildroot}%{_docdir}/%{name} \
     && xz -c tests/test-suite.log \
          > %{buildroot}%{_docdir}/%{name}/test-suite.log.xz