diff --git a/examples/ReadAndWrite/ReadAndWrite.ino b/examples/ReadAndWrite/ReadAndWrite.ino
index 690771b..6d7b6b6 100644
--- a/examples/ReadAndWrite/ReadAndWrite.ino
+++ b/examples/ReadAndWrite/ReadAndWrite.ino
@@ -42,6 +42,7 @@ MFRC522::MIFARE_Key key;
  */
 void setup() {
     Serial.begin(9600); // Initialize serial communications with the PC
+    while (!Serial);    // Do nothing if no serial port is opened (added for Arduinos based on ATMEGA32U4)
     SPI.begin();        // Init SPI bus
     mfrc522.PCD_Init(); // Init MFRC522 card