diff --git a/utils.sh b/utils.sh
--- a/utils.sh
+++ b/utils.sh
@@ -260,6 +260,6 @@
     done < <(cat "${language_list}")
 
     if [ -e "${basedir}/po/CMakeLists.txt" ]; then
-        echo "add_subdirectory(po)" >>${basedir}/CMakeLists.txt
+        echo -e "include(ECMOptionalAddSubdirectory)\necm_optional_add_subdirectory(po)" >>${basedir}/CMakeLists.txt
     fi
 }