diff --git a/External/Photospp/cmt/requirements b/External/Photospp/cmt/requirements
index 3f24bb1f0d9fe17a7a7ae319145e0d7cb394b931..cd31cde69c542f89973b92f34d08724a32c796d6 100644
--- a/External/Photospp/cmt/requirements
+++ b/External/Photospp/cmt/requirements
@@ -6,7 +6,7 @@ use AtlasExternalArea     AtlasExternalArea-*     External
 use AtlasHepMC            AtlasHepMC-*            External
 use LCG_Configuration
 
-macro Photospp_home "$(LCG_ROOT)/external/MCGenerators_lcgcmt$(LCG_config_version)/photos++"
+macro Photospp_home "$(LCG_external)/MCGenerators/photos++"
 macro Photospp_version "3.52"
 macro Photospp_native_version "$(Photospp_version)_lcgcmt$(LCG_config_version)"
 macro Photospp_system "$(LCG_ext_system)"