diff --git a/libraries/AP_HAL_SITL/Scheduler.cpp b/libraries/AP_HAL_SITL/Scheduler.cpp
index 6382c5c240..abdd570e21 100644
--- a/libraries/AP_HAL_SITL/Scheduler.cpp
+++ b/libraries/AP_HAL_SITL/Scheduler.cpp
@@ -52,20 +52,11 @@ void Scheduler::delay(uint16_t ms)
         delay_microseconds(1000);
         ms--;
         if (_min_delay_cb_ms <= ms) {
-            if (_delay_cb) {
-                _delay_cb();
-            }
+            call_delay_cb();
         }
     }
 }
 
-void Scheduler::register_delay_callback(AP_HAL::Proc proc,
-        uint16_t min_time_ms)
-{
-    _delay_cb = proc;
-    _min_delay_cb_ms = min_time_ms;
-}
-
 void Scheduler::register_timer_process(AP_HAL::MemberProc proc)
 {
     for (uint8_t i = 0; i < _num_timer_procs; i++) {
diff --git a/libraries/AP_HAL_SITL/Scheduler.h b/libraries/AP_HAL_SITL/Scheduler.h
index effea60193..6d154d7255 100644
--- a/libraries/AP_HAL_SITL/Scheduler.h
+++ b/libraries/AP_HAL_SITL/Scheduler.h
@@ -20,7 +20,6 @@ public:
     void init();
     void delay(uint16_t ms);
     void delay_microseconds(uint16_t us);
-    void register_delay_callback(AP_HAL::Proc, uint16_t min_time_ms);
 
     void register_timer_process(AP_HAL::MemberProc);
     void register_io_process(AP_HAL::MemberProc);
@@ -55,8 +54,6 @@ public:
 private:
     SITL_State *_sitlState;
     uint8_t _nested_atomic_ctr;
-    AP_HAL::Proc _delay_cb;
-    uint16_t _min_delay_cb_ms;
     static AP_HAL::Proc _failsafe;
 
     static void _run_timer_procs(bool called_from_isr);