diff --git a/modules/TDEMacros.cmake b/modules/TDEMacros.cmake
index fd1da82..d19fc59 100644
--- a/modules/TDEMacros.cmake
+++ b/modules/TDEMacros.cmake
@@ -2273,6 +2273,7 @@ macro( tde_create_handbook )
       WORKING_DIRECTORY "${_binary_basedir}"
     )
 
+    string( REPLACE "@" "_" _target "${_target}" )
     add_custom_target( ${_target} ALL DEPENDS ${_binary_basedir}/index.cache.bz2 )
 
     list( APPEND _srcs ${_binary_basedir}/index.cache.bz2 )