diff --git a/src/keyer.cpp b/src/keyer.cpp
index 453098b..5e06b7b 100644
--- a/src/keyer.cpp
+++ b/src/keyer.cpp
@@ -48,7 +48,7 @@ void Keyer::setSpeed(uint8_t wpm)
     m_elementDuration = calcElementDurationUs(wpm);
 }
 
-void Keyer::sendMessage(std::string &msg)
+void Keyer::sendMessage(std::string msg)
 {
     std::string morse = messageToMorse(msg);
     printf("Morse (%i): %s\n", morse.length(), morse.c_str());
diff --git a/src/keyer.h b/src/keyer.h
index 05cef60..3b7e2ba 100644
--- a/src/keyer.h
+++ b/src/keyer.h
@@ -14,7 +14,7 @@ class Keyer final
 
     void setMode(Mode mode) { m_mode = mode; }
     void setSpeed(uint8_t wpm);
-    void sendMessage(std::string &msg);
+    void sendMessage(std::string msg);
 
     void run();
     void stop();