diff --git a/bloom/generators/rpm/templates/ament_cmake/template.spec.em b/bloom/generators/rpm/templates/ament_cmake/template.spec.em
index bebb96b6..5d2afb37 100644
--- a/bloom/generators/rpm/templates/ament_cmake/template.spec.em
+++ b/bloom/generators/rpm/templates/ament_cmake/template.spec.em
@@ -5,6 +5,8 @@
 %global __provides_exclude_from ^@(InstallationPrefix)/.*$
 %global __requires_exclude_from ^@(InstallationPrefix)/.*$
 
+%global __cmake_in_source_build 1
+
 Name:           @(Package)
 Version:        @(Version)
 Release:        @(RPMInc)%{?dist}%{?release_suffix}
diff --git a/bloom/generators/rpm/templates/cmake/template.spec.em b/bloom/generators/rpm/templates/cmake/template.spec.em
index b1217d05..3464a0bc 100644
--- a/bloom/generators/rpm/templates/cmake/template.spec.em
+++ b/bloom/generators/rpm/templates/cmake/template.spec.em
@@ -5,6 +5,8 @@
 %global __provides_exclude_from ^@(InstallationPrefix)/.*$
 %global __requires_exclude_from ^@(InstallationPrefix)/.*$
 
+%global __cmake_in_source_build 1
+
 Name:           @(Package)
 Version:        @(Version)
 Release:        @(RPMInc)%{?dist}%{?release_suffix}