diff --git a/avogadro2.spec b/avogadro2.spec
index 193fdea..70f03a5 100644
--- a/avogadro2.spec
+++ b/avogadro2.spec
@@ -1,3 +1,5 @@
+%global __cmake_in_source_build 1
+
 # Use devtoolset 8
 %if 0%{?rhel} && 0%{?rhel} == 7
 %global dts devtoolset-8-