diff --git a/libraries/FastSerial/FastSerial.cpp b/libraries/FastSerial/FastSerial.cpp
index 96c613d41c..99553a877b 100644
--- a/libraries/FastSerial/FastSerial.cpp
+++ b/libraries/FastSerial/FastSerial.cpp
@@ -150,7 +150,7 @@ void FastSerial::end()
 }
 
 
-uint8_t
+int
 FastSerial::available(void)
 {
         return((RX_BUFFER_SIZE + _rxBuffer.head - _rxBuffer.tail) % RX_BUFFER_SIZE);
diff --git a/libraries/FastSerial/FastSerial.h b/libraries/FastSerial/FastSerial.h
index 6188986b1f..9849e4a655 100644
--- a/libraries/FastSerial/FastSerial.h
+++ b/libraries/FastSerial/FastSerial.h
@@ -45,11 +45,14 @@
 #define FastSerial_h
 
 // disable the stock Arduino serial driver
+#ifdef HardwareSerial_h
+# error Must include FastSerial.h before the Arduino serial driver is defined.
+#endif
 #define HardwareSerial_h
 
 #include <inttypes.h>
 #include <stdio.h>
-#include <Print.h>
+#include <Stream.h>
 #include <avr/interrupt.h>
 
 //
@@ -82,7 +85,7 @@ extern class FastSerial Serial2;
 extern class FastSerial Serial3;
 
 
-class FastSerial : public Print {
+class FastSerial : public Stream {
 public:
         FastSerial(const uint8_t portNumber,
                    volatile uint8_t *ubrrh,
@@ -97,12 +100,12 @@ public:
         // Serial API
         void            begin(long baud);
         void            end(void);
-        uint8_t         available(void);
+        int             available(void);
         int             read(void);
         void            flush(void);
         void            write(uint8_t c);
         void            write(const uint8_t *buffer, int count);
-        using Print::write;
+        using Stream::write;
 
         // stdio extensions
         int             printf(const char *fmt, ...);
diff --git a/libraries/FastSerial/examples/FastSerial/FastSerial.pde b/libraries/FastSerial/examples/FastSerial/FastSerial.pde
index 2923645ebb..4cda83940b 100644
--- a/libraries/FastSerial/examples/FastSerial/FastSerial.pde
+++ b/libraries/FastSerial/examples/FastSerial/FastSerial.pde
@@ -18,7 +18,7 @@
 // Create a FastSerial driver that looks just like the stock Arduino
 // driver.
 //
-FastSerial      Serial;
+FastSerialPort0(Serial);
 
 //
 // To create a driver for a different serial port, on a board that