diff --git a/src/Module.h b/src/Module.h
index 3a7b098d..2492c1a4 100644
--- a/src/Module.h
+++ b/src/Module.h
@@ -190,7 +190,7 @@ class Module {
 
       \param numBytes Number of bytes to transfer.
     */
-    void SPItransfer(uint8_t cmd, uint8_t reg, uint8_t* dataOut, uint8_t* dataIn, uint8_t numBytes);
+    virtual void SPItransfer(uint8_t cmd, uint8_t reg, uint8_t* dataOut, uint8_t* dataIn, uint8_t numBytes);
 
     // pin number access methods