diff --git a/cores/arduino/HardwareSerial.cpp b/cores/arduino/HardwareSerial.cpp
index 91c79d3..9f5ed50 100644
--- a/cores/arduino/HardwareSerial.cpp
+++ b/cores/arduino/HardwareSerial.cpp
@@ -86,6 +86,8 @@ inline void store_char(unsigned char c, ring_buffer *buffer)
 	!defined(SIG_UART_RECV)
   #error Don't know what the Data Received vector is called for the first UART
 #else
+  void serialEvent() __attribute__((weak));
+  void serialEvent() {}
 #if defined(USART_RX_vect)
   SIGNAL(USART_RX_vect)
 #elif defined(SIG_USART0_RECV)
@@ -106,36 +108,44 @@ inline void store_char(unsigned char c, ring_buffer *buffer)
     #error UDR not defined
   #endif
     store_char(c, &rx_buffer);
+	serialEvent();
   }
 #endif
 
-//#if defined(SIG_USART1_RECV)
 #if defined(USART1_RX_vect)
-  //SIGNAL(SIG_USART1_RECV)
+  void serialEvent1() __attribute__((weak));
+  void serialEvent1() {}
   SIGNAL(USART1_RX_vect)
   {
     unsigned char c = UDR1;
     store_char(c, &rx_buffer1);
+	serialEvent1();
   }
 #elif defined(SIG_USART1_RECV)
   #error SIG_USART1_RECV
 #endif
 
 #if defined(USART2_RX_vect) && defined(UDR2)
+  void serialEvent2() __attribute__((weak));
+  void serialEvent2() {}
   SIGNAL(USART2_RX_vect)
   {
     unsigned char c = UDR2;
     store_char(c, &rx_buffer2);
+	serialEvent2();
   }
 #elif defined(SIG_USART2_RECV)
   #error SIG_USART2_RECV
 #endif
 
 #if defined(USART3_RX_vect) && defined(UDR3)
+  void serialEvent3() __attribute__((weak));
+  void serialEvent3() {}
   SIGNAL(USART3_RX_vect)
   {
     unsigned char c = UDR3;
     store_char(c, &rx_buffer3);
+	serialEvent3();
   }
 #elif defined(SIG_USART3_RECV)
   #error SIG_USART3_RECV