diff --git a/libraries/AP_HAL_Linux/Scheduler.cpp b/libraries/AP_HAL_Linux/Scheduler.cpp
index 90ce75861e..f242745882 100644
--- a/libraries/AP_HAL_Linux/Scheduler.cpp
+++ b/libraries/AP_HAL_Linux/Scheduler.cpp
@@ -419,6 +419,11 @@ bool Scheduler::in_timerprocess()
     return _in_timer_proc;
 }
 
+bool Scheduler::in_main_thread() const
+{
+    return pthread_equal(pthread_self(), _main_ctx);
+}
+
 void Scheduler::_wait_all_threads()
 {
     int r = pthread_barrier_wait(&_initialized_barrier);
diff --git a/libraries/AP_HAL_Linux/Scheduler.h b/libraries/AP_HAL_Linux/Scheduler.h
index bb991a8aa8..4085743bc9 100644
--- a/libraries/AP_HAL_Linux/Scheduler.h
+++ b/libraries/AP_HAL_Linux/Scheduler.h
@@ -37,6 +37,7 @@ public:
     void     resume_timer_procs();
 
     bool     in_timerprocess();
+    bool     in_main_thread() const override;
 
     void     register_timer_failsafe(AP_HAL::Proc, uint32_t period_us);