diff --git a/libraries/AP_HAL_ChibiOS/RCInput.cpp b/libraries/AP_HAL_ChibiOS/RCInput.cpp
index fdbbeb2b64..79be9b47bf 100644
--- a/libraries/AP_HAL_ChibiOS/RCInput.cpp
+++ b/libraries/AP_HAL_ChibiOS/RCInput.cpp
@@ -127,6 +127,7 @@ void RCInput::_timer_tick(void)
         rcin_mutex.take(HAL_SEMAPHORE_BLOCK_FOREVER);
         _rcin_timestamp_last_signal = AP_HAL::micros();
         _num_channels = rcin_prot.num_channels();
+        _num_channels = MIN(_num_channels, RC_INPUT_MAX_CHANNELS);
         for (uint8_t i=0; i<_num_channels; i++) {
             _rc_values[i] = rcin_prot.read(i);
         }
@@ -140,6 +141,7 @@ void RCInput::_timer_tick(void)
         rcin_mutex.take(HAL_SEMAPHORE_BLOCK_FOREVER);
         _rcin_timestamp_last_signal = last_radio_us;
         _num_channels = radio->num_channels();
+        _num_channels = MIN(_num_channels, RC_INPUT_MAX_CHANNELS);
         for (uint8_t i=0; i<_num_channels; i++) {
             _rc_values[i] = radio->read(i);
         }