diff --git a/msgpack.spec b/msgpack.spec
index ce34eec..9716333 100644
--- a/msgpack.spec
+++ b/msgpack.spec
@@ -1,3 +1,5 @@
+%global __cmake_in_source_build 1
+
 Name:		msgpack
 Version:	3.1.0
 Release:	6%{?dist}