diff --git a/iptraf-ng.changes b/iptraf-ng.changes
index e2c8547..3e463f7 100644
--- a/iptraf-ng.changes
+++ b/iptraf-ng.changes
@@ -1,3 +1,8 @@
+-------------------------------------------------------------------
+Wed Nov 11 10:52:12 UTC 2020 - Martin Wilck <mwilck@suse.com>
+
+- Fix build error on SLE12 (%make_build not defined) 
+
 -------------------------------------------------------------------
 Sun Aug 16 14:11:17 UTC 2020 - Dirk Mueller <dmueller@suse.com>
 
diff --git a/iptraf-ng.spec b/iptraf-ng.spec
index 93af635..53503e4 100644
--- a/iptraf-ng.spec
+++ b/iptraf-ng.spec
@@ -41,7 +41,7 @@ breakdowns, and LAN station packet and byte counts.
 %autosetup -n %name-%version -p1
 
 %build
-%make_build CFLAGS="%optflags -D_GNU_SOURCE"
+%{?make_build}%{!?make_build:make %{?_smp_mflags}} CFLAGS="%optflags -D_GNU_SOURCE"
 
 %install
 %make_install prefix="%_prefix" V=1