diff --git a/Transceiver52M/radioInterface.h b/Transceiver52M/radioInterface.h
index 83e00b9..b12c187 100644
--- a/Transceiver52M/radioInterface.h
+++ b/Transceiver52M/radioInterface.h
@@ -107,7 +107,7 @@
   virtual bool tuneRx(double freq, size_t chan = 0);
 
   /** set receive gain */
-  double setRxGain(double dB, size_t chan = 0);
+  virtual double setRxGain(double dB, size_t chan = 0);
 
   /** drive transmission of GSM bursts */
   void driveTransmitRadio(std::vector<signalVector *> &bursts,
@@ -182,5 +182,5 @@
 
   bool tuneTx(double freq, size_t chan);
   bool tuneRx(double freq, size_t chan);
-  double setRxGain(double dB, size_t chan);
+  virtual double setRxGain(double dB, size_t chan);
 };