diff --git a/src/timer/timer.h b/src/timer/timer.h
--- a/src/timer/timer.h
+++ b/src/timer/timer.h
@@ -12,7 +12,6 @@
 
 #include "timer_manager.h"
 
-#include <functional>
 
 /**
  * The base where every other type of timer is derived from.