diff --git a/rxtx-java.changes b/rxtx-java.changes
index 510e3b5..a73bb50 100644
--- a/rxtx-java.changes
+++ b/rxtx-java.changes
@@ -1,3 +1,9 @@
+-------------------------------------------------------------------
+Tue Jul 27 13:11:40 UTC 2021 - Fridrich Strba <fstrba@suse.com>
+
+- Define %%make_build for systems that don't have it defined in
+  rpm macros
+
 -------------------------------------------------------------------
 Thu Mar 26 10:02:18 UTC 2020 - Fridrich Strba <fstrba@suse.com>
 
diff --git a/rxtx-java.spec b/rxtx-java.spec
index f9b89ba..e95ec93 100644
--- a/rxtx-java.spec
+++ b/rxtx-java.spec
@@ -1,7 +1,7 @@
 #
 # spec file for package rxtx-java
 #
-# Copyright (c) 2020 SUSE LLC
+# Copyright (c) 2021 SUSE LLC
 #
 # All modifications and additions to the file contributed by third parties
 # remain the property of their copyright owners, unless otherwise agreed
@@ -16,6 +16,7 @@
 #
 
 
+%{!?make_build:%global make_build make %{?_smp_mflags}}
 %define src_name rxtx
 %define upver 2.2
 %define prever pre2