diff --git a/libraries/AP_HAL_Empty/SPIDriver.cpp b/libraries/AP_HAL_Empty/SPIDriver.cpp
index 9d432faf9e..332e6f958e 100644
--- a/libraries/AP_HAL_Empty/SPIDriver.cpp
+++ b/libraries/AP_HAL_Empty/SPIDriver.cpp
@@ -29,6 +29,10 @@ uint8_t EmptySPIDeviceDriver::transfer (uint8_t data)
     return 0;
 }
 
+void EmptySPIDeviceDriver::transfer (const uint8_t *data, uint16_t len)
+{
+}
+
 EmptySPIDeviceManager::EmptySPIDeviceManager()
 {}
 
diff --git a/libraries/AP_HAL_Empty/SPIDriver.h b/libraries/AP_HAL_Empty/SPIDriver.h
index ac87320fdf..dcd0cd6fae 100644
--- a/libraries/AP_HAL_Empty/SPIDriver.h
+++ b/libraries/AP_HAL_Empty/SPIDriver.h
@@ -15,6 +15,7 @@ public:
     void cs_assert();
     void cs_release();
     uint8_t transfer (uint8_t data);
+    void transfer (const uint8_t *data, uint16_t len);
 private:
     EmptySemaphore _semaphore;
 };