diff --git a/src/update-cb.hh b/src/update-cb.hh
index 182239f8..e1bc021e 100644
--- a/src/update-cb.hh
+++ b/src/update-cb.hh
@@ -94,6 +94,9 @@ namespace conky {
 
 			friend void conky::run_all_callbacks();
 
+			template<typename Callback>
+			friend class conky::callback_handle;
+
 		protected:
 			callback_base(size_t hash_, uint32_t period_, bool wait_, bool use_pipe)
 				: thread(NULL), hash(hash_), period(period_), remaining(0),