diff --git a/MozillaFirefox.spec b/MozillaFirefox.spec
index 15a70e8c..0883c91e 100644
--- a/MozillaFirefox.spec
+++ b/MozillaFirefox.spec
@@ -416,7 +416,9 @@ source ./.obsenv.sh
 cat << EOF > $MOZCONFIG
 mk_add_options MOZILLA_OFFICIAL=1
 mk_add_options BUILD_OFFICIAL=1
-%ifnarch %ix86
+%ifarch %ix86
+mk_add_options MOZ_MAKE_FLAGS=-j1
+%else
 mk_add_options MOZ_MAKE_FLAGS=%{?jobs:-j%jobs}
 %endif
 mk_add_options MOZ_OBJDIR=@TOPSRCDIR@/../obj