diff --git a/stunnel.changes b/stunnel.changes
index 8ac7f88..a051c7e 100644
--- a/stunnel.changes
+++ b/stunnel.changes
@@ -1,3 +1,9 @@
+-------------------------------------------------------------------
+Wed Apr 26 09:43:10 UTC 2023 - Andreas Vetter <vetter@physik.uni-wuerzburg.de>
+
+- Fix build on SLE12:
+  - add macro make_build
+
 -------------------------------------------------------------------
 Mon Apr  3 20:05:38 UTC 2023 - Dirk Müller <dmueller@suse.com>
 
diff --git a/stunnel.spec b/stunnel.spec
index 2bc1e3b..5848588 100644
--- a/stunnel.spec
+++ b/stunnel.spec
@@ -83,6 +83,9 @@ sed -i 's/-m 1770//g' tools/Makefile.in
 %configure \
 	--disable-static \
 	--bindir=%{_sbindir}
+%if 0%{?sle_version} < 150000
+  %define make_build %{__make} -O %{?_smp_mflags}
+%endif
 %make_build LDADD="-pie -Wl,-z,defs,-z,relro,-z,now"
 
 %install