diff --git a/groff.spec b/groff.spec
index a30db6c..fe214b2 100644
--- a/groff.spec
+++ b/groff.spec
@@ -114,7 +114,7 @@ make
 (cd doc && makeinfo groff.texinfo)
 %if %{with_x}
 cd src/xditview
-xmkmf && make
+xmkmf && make %{?_smp_mflags}
 %endif
 
 %install