diff --git a/sdevent/event.hpp b/sdevent/event.hpp
index ac9a13d..3e97ce7 100644
--- a/sdevent/event.hpp
+++ b/sdevent/event.hpp
@@ -11,6 +11,10 @@
 {
 namespace event
 {
+namespace io
+{
+class IO;
+} // namespace io
 
 using EventPtr = sd_event*;
 class Event;
@@ -100,6 +104,8 @@
             return steady_clock::time_point(d);
         }
 
+        friend class io::IO;
+
     private:
 
         EventPtr get()