diff --git a/libraries/AP_HAL_ChibiOS/RCOutput.cpp b/libraries/AP_HAL_ChibiOS/RCOutput.cpp
index a7a2e319b4..fd3d5cd81b 100644
--- a/libraries/AP_HAL_ChibiOS/RCOutput.cpp
+++ b/libraries/AP_HAL_ChibiOS/RCOutput.cpp
@@ -2520,9 +2520,9 @@ void RCOutput::serial_led_send(const uint16_t chan)
     }
 
     if (grp->prepared_send) {
-        chEvtSignal(led_thread_ctx, EVT_LED_SEND);
         grp->serial_led_pending = true;
         serial_led_pending = true;
+        chEvtSignal(led_thread_ctx, EVT_LED_SEND);
     }
 }