diff --git a/RFM69.cpp b/RFM69.cpp
index 5097069..6824fd1 100644
--- a/RFM69.cpp
+++ b/RFM69.cpp
@@ -226,7 +226,7 @@ void RFM69::send(uint8_t toAddress, const void* buffer, uint8_t bufferSize, bool
 // The reason for the semi-automaton is that the lib is interrupt driven and
 // requires user action to read the received data and decide what to do with it
 // replies usually take only 5..8ms at 50kbps@915MHz
-bool RFM69::sendWithRetry(uint8_t toAddress, const void* buffer, uint8_t bufferSize, uint8_t retries, uint8_t retryWaitTime) {
+bool RFM69::sendWithRetry(uint8_t toAddress, const void* buffer, uint8_t bufferSize, uint8_t retries, uint16_t retryWaitTime) {
   uint32_t sentTime;
   for (uint8_t i = 0; i <= retries; i++)
   {
diff --git a/RFM69.h b/RFM69.h
index d60d1df..7663fe2 100644
--- a/RFM69.h
+++ b/RFM69.h
@@ -100,7 +100,7 @@ class RFM69 {
     void setNetwork(uint8_t networkID);
     bool canSend();
     virtual void send(uint8_t toAddress, const void* buffer, uint8_t bufferSize, bool requestACK=false);
-    virtual bool sendWithRetry(uint8_t toAddress, const void* buffer, uint8_t bufferSize, uint8_t retries=2, uint8_t retryWaitTime=40); // 40ms roundtrip req for 61byte packets
+    virtual bool sendWithRetry(uint8_t toAddress, const void* buffer, uint8_t bufferSize, uint8_t retries=2, uint16_t retryWaitTime=40); // 40ms roundtrip req for 61byte packets
     virtual bool receiveDone();
     bool ACKReceived(uint8_t fromNodeID);
     bool ACKRequested();