diff --git a/libraries/AP_HAL_ChibiOS/Scheduler.cpp b/libraries/AP_HAL_ChibiOS/Scheduler.cpp
index 36b1d7a551..5d4717eee0 100644
--- a/libraries/AP_HAL_ChibiOS/Scheduler.cpp
+++ b/libraries/AP_HAL_ChibiOS/Scheduler.cpp
@@ -752,7 +752,7 @@ bool Scheduler::thread_create(AP_HAL::MemberProc proc, const char *name, uint32_
   be used to prevent watchdog reset during expected long delays
   A value of zero cancels the previous expected delay
 */
-void Scheduler::_expect_delay_ms(uint32_t ms)
+void Scheduler::expect_delay_ms(uint32_t ms)
 {
     if (!in_main_thread()) {
         // only for main thread
@@ -762,8 +762,6 @@ void Scheduler::_expect_delay_ms(uint32_t ms)
     // pat once immediately
     watchdog_pat();
 
-    WITH_SEMAPHORE(expect_delay_sem);
-
     if (ms == 0) {
         if (expect_delay_nesting > 0) {
             expect_delay_nesting--;
@@ -789,18 +787,6 @@ void Scheduler::_expect_delay_ms(uint32_t ms)
     }
 }
 
-/*
-  this is _expect_delay_ms() with check that we are in the main thread
- */
-void Scheduler::expect_delay_ms(uint32_t ms)
-{
-    if (!in_main_thread()) {
-        // only for main thread
-        return;
-    }
-    _expect_delay_ms(ms);
-}
-
 // pat the watchdog
 void Scheduler::watchdog_pat(void)
 {
diff --git a/libraries/AP_HAL_ChibiOS/Scheduler.h b/libraries/AP_HAL_ChibiOS/Scheduler.h
index 47052d79d7..f0178b3495 100644
--- a/libraries/AP_HAL_ChibiOS/Scheduler.h
+++ b/libraries/AP_HAL_ChibiOS/Scheduler.h
@@ -115,7 +115,6 @@ public:
       be used to prevent watchdog reset during expected long delays
       A value of zero cancels the previous expected delay
      */
-    void     _expect_delay_ms(uint32_t ms);
     void     expect_delay_ms(uint32_t ms) override;
 
     /*
@@ -153,7 +152,6 @@ private:
     uint32_t expect_delay_start;
     uint32_t expect_delay_length;
     uint32_t expect_delay_nesting;
-    HAL_Semaphore expect_delay_sem;
 
     AP_HAL::MemberProc _timer_proc[CHIBIOS_SCHEDULER_MAX_TIMER_PROCS];
     uint8_t _num_timer_procs;