diff --git a/GeographicLib.spec b/GeographicLib.spec
index f57a8e8..b4d0313 100644
--- a/GeographicLib.spec
+++ b/GeographicLib.spec
@@ -1,3 +1,6 @@
+# Needed as builddir needs to be the same on every arch, otherwise doxygen produces differently named outputs
+%global __cmake_in_source_build 1
+
 #global commit 2a6ccdf99f9b580aff4ef4725720172235fa9da0
 #global shortcommit %(c=%{commit}; echo ${c:0:7})