diff --git a/libraries/AP_HAL/SPIDriver.h b/libraries/AP_HAL/SPIDriver.h
index 8208af3f62..a10a4c5513 100644
--- a/libraries/AP_HAL/SPIDriver.h
+++ b/libraries/AP_HAL/SPIDriver.h
@@ -20,6 +20,8 @@ class AP_HAL::SPIDeviceDriver {
 public:
     virtual void init() = 0;
     virtual AP_HAL::Semaphore* get_semaphore() = 0;
+    virtual void transaction(const uint8_t *tx, uint8_t *rx, uint16_t len) = 0;
+
     virtual void cs_assert() = 0;
     virtual void cs_release() = 0;
     virtual uint8_t transfer (uint8_t data) = 0;