diff --git a/cores/arduino/HardwareSerial.cpp b/cores/arduino/HardwareSerial.cpp
index e165136..d96b47f 100644
--- a/cores/arduino/HardwareSerial.cpp
+++ b/cores/arduino/HardwareSerial.cpp
@@ -152,7 +152,7 @@ void HardwareSerial::end()
 
 int HardwareSerial::available(void)
 {
-  return (unsigned int)(SERIAL_RX_BUFFER_SIZE + _rx_buffer_head - _rx_buffer_tail) % SERIAL_RX_BUFFER_SIZE;
+  return (int)(SERIAL_RX_BUFFER_SIZE + _rx_buffer_head - _rx_buffer_tail) % SERIAL_RX_BUFFER_SIZE;
 }
 
 int HardwareSerial::peek(void)
diff --git a/libraries/SoftwareSerial/SoftwareSerial.cpp b/libraries/SoftwareSerial/SoftwareSerial.cpp
index 64496fe..d1f6c92 100644
--- a/libraries/SoftwareSerial/SoftwareSerial.cpp
+++ b/libraries/SoftwareSerial/SoftwareSerial.cpp
@@ -355,7 +355,7 @@ SoftwareSerial::~SoftwareSerial()
 void SoftwareSerial::setTX(uint8_t tx)
 {
   pinMode(tx, OUTPUT);
-  digitalWrite(tx, HIGH);
+  digitalWrite(tx, _inverse_logic ? LOW : HIGH);
   _transmitBitMask = digitalPinToBitMask(tx);
   uint8_t port = digitalPinToPort(tx);
   _transmitPortRegister = portOutputRegister(port);