diff --git a/libraries/AP_HAL_Linux/Scheduler.cpp b/libraries/AP_HAL_Linux/Scheduler.cpp
index 562191f96a..342327c67c 100644
--- a/libraries/AP_HAL_Linux/Scheduler.cpp
+++ b/libraries/AP_HAL_Linux/Scheduler.cpp
@@ -371,6 +371,7 @@ void Scheduler::_run_uarts()
 #else
     UARTDriver::from(hal.uartC)->_timer_tick();
 #endif
+    UARTDriver::from(hal.uartD)->_timer_tick();
     UARTDriver::from(hal.uartE)->_timer_tick();
     UARTDriver::from(hal.uartF)->_timer_tick();
 }