diff --git a/Installation/CMakeLists.txt b/Installation/CMakeLists.txt
index 0ff23d0357b..d877ac2ce45 100644
--- a/Installation/CMakeLists.txt
+++ b/Installation/CMakeLists.txt
@@ -1080,18 +1080,22 @@ You must disable CGAL_ENABLE_CHECK_HEADERS.")
     endif()
   endforeach()
   #compare the computed list of headers with the stored one to check for changes
+
   list(SORT check_list_of_documented_headers)
   list(REMOVE_DUPLICATES check_list_of_documented_headers)
   foreach( hdr ${list_of_documented_headers})
     if(NOT ${hdr} IN_LIST check_list_of_documented_headers)
+      message("${hdr} is not in check")
       list(APPEND not_in_list "${hdr}")
     endif()
   endforeach()
   foreach( hdr ${check_list_of_documented_headers})
     if(NOT ${hdr} IN_LIST list_of_documented_headers)
+      message("${hdr} is not in list")
       list(APPEND list_in_not "${hdr}")
     endif()
   endforeach()
+
   if(not_in_list OR list_in_not)
     message("Header files list do not match : ")
     if(not_in_list)