diff --git a/_multibuild b/_multibuild
index 37cda36..4cc652f 100644
--- a/_multibuild
+++ b/_multibuild
@@ -1,3 +1,4 @@
 <multibuild>
   <package>base</package>
+  <package>extra</package>
 </multibuild>
diff --git a/boost.changes b/boost.changes
index 3420940..9202993 100644
--- a/boost.changes
+++ b/boost.changes
@@ -1,3 +1,8 @@
+-------------------------------------------------------------------
+Mon Jan 14 14:57:14 UTC 2019 - adam.majer@suse.de
+
+- Simplify _multibuild flavours
+
 -------------------------------------------------------------------
 Fri Dec 14 01:26:04 UTC 2018 - adam.majer@suse.de
 
diff --git a/boost.spec b/boost.spec
index 7502264..3ea5a96 100644
--- a/boost.spec
+++ b/boost.spec
@@ -1,7 +1,7 @@
 #
 # spec file for package boost
 #
-# Copyright (c) 2018 SUSE LINUX GmbH, Nuernberg, Germany.
+# Copyright (c) 2019 SUSE LINUX GmbH, Nuernberg, Germany.
 #
 # All modifications and additions to the file contributed by third parties
 # remain the property of their copyright owners, unless otherwise agreed
@@ -29,13 +29,21 @@
 %if 0%{?suse_version} < 1500
   %define python2_sitearch %{python_sitearch}
 %endif
+
+%if "@BUILD_FLAVOR@" == ""
+ExclusiveArch:  nothing_here
+%endif
+
 %if "@BUILD_FLAVOR@" == "base"
 %define build_base 1
 %define name_suffix -base
-%else
-%define build_base 0
-%define name_suffix %{nil}
 %endif
+
+%if "@BUILD_FLAVOR@" == "extra"
+%define build_base 0
+%define name_suffix -extra
+%endif
+
 # Build with OpenMPI
 %if 0%{?suse_version} >= 1330
   # OpenMPI >= 2 is not available on ppc64be