diff --git a/pipettes/firmware/main.cpp b/pipettes/firmware/main.cpp
index b58730511..839fd53bf 100644
--- a/pipettes/firmware/main.cpp
+++ b/pipettes/firmware/main.cpp
@@ -143,7 +143,7 @@ static auto tail_accessor =
 extern "C" void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin) {
     if (GPIO_Pin == tip_sense_gpio_primary.pin) {
         static_cast<void>(
-            sensor_queue_client.tip_notification_queue_rear->try_write_isr(
+            if(sensor_queue_client.tip_notification_queue_rear) sensor_queue_client.tip_notification_queue_rear->try_write_isr(
                 sensors::tip_presence::TipStatusChangeDetected{}));
     } else if (ok_for_secondary &&
                GPIO_Pin ==