diff --git a/Adafruit_USBD_CDC.cpp b/Adafruit_USBD_CDC.cpp
index b3b2399..0283ddf 100644
--- a/Adafruit_USBD_CDC.cpp
+++ b/Adafruit_USBD_CDC.cpp
@@ -99,6 +99,11 @@ uint8_t Adafruit_USBD_CDC::numbits(void)
   return coding.data_bits;
 }
 
+int Adafruit_USBD_CDC::dtr(void)
+{
+  return tud_cdc_connected();
+}
+
 Adafruit_USBD_CDC::operator bool()
 {
   bool ret = tud_cdc_connected();
diff --git a/Adafruit_USBD_CDC.h b/Adafruit_USBD_CDC.h
index 6b4663d..b704107 100644
--- a/Adafruit_USBD_CDC.h
+++ b/Adafruit_USBD_CDC.h
@@ -46,6 +46,7 @@ class Adafruit_USBD_CDC : public Stream, public Adafruit_USBD_Interface
 	uint8_t  stopbits(void);
 	uint8_t  paritytype(void);
 	uint8_t  numbits(void);
+	int      dtr(void);
 
 	virtual int    available(void);
 	virtual int    peek(void);