diff --git a/tidy.spec b/tidy.spec
index efcf63c..bb806c7 100644
--- a/tidy.spec
+++ b/tidy.spec
@@ -1,4 +1,4 @@
-
+%global __cmake_in_source_build 1
 %global libname libtidy
 %global upname tidy-html5
 %global tidy_compat_headers 1