diff --git a/rb_libtorrent.spec b/rb_libtorrent.spec
index c205b56..7231d1a 100644
--- a/rb_libtorrent.spec
+++ b/rb_libtorrent.spec
@@ -194,7 +194,7 @@ echo "set (CTEST_CUSTOM_TESTS_IGNORE
   "test_torrent"
   "test_resume"
 )" > CTestCustom.cmake
-ctest %{?_smp_mflags}
+ctest
 popd
 %endif