diff --git a/RFM69.cpp b/RFM69.cpp
index 3f15e1e..9c74061 100644
--- a/RFM69.cpp
+++ b/RFM69.cpp
@@ -1075,7 +1075,7 @@ void RFM69::listenModeApplyHighSpeedSettings()
 //=============================================================================
 // sendBurst() - send a burst of packets to a sleeping listening node (or all)
 //=============================================================================
-void RFM69::listenModeSendBurst( uint8_t targetNode, void* buffer, uint8_t size )
+void RFM69::listenModeSendBurst( uint8_t targetNode, const void* buffer, uint8_t size )
 {
   detachInterrupt(_interruptNum);
   setMode(RF69_MODE_STANDBY);
diff --git a/RFM69.h b/RFM69.h
index f62815d..e358f34 100644
--- a/RFM69.h
+++ b/RFM69.h
@@ -259,7 +259,7 @@ class RFM69 {
     // is transmitted to the receiver, and it is expected that the receiver
     // wait for the burst to end before attempting a reply.
     // See RF69_LISTEN_BURST_REMAINING_MS above.
-    void listenModeSendBurst(uint8_t targetNode, void* buffer, uint8_t size);
+    void listenModeSendBurst(uint8_t targetNode, const void* buffer, uint8_t size);
 
   protected:
     void listenModeInterruptHandler(void);