diff --git a/libraries/SoftwareSerial/examples/TwoPortReceive/TwoPortReceive.ino b/libraries/SoftwareSerial/examples/TwoPortReceive/TwoPortReceive.ino
index f88e58acfc..b386edef65 100644
--- a/libraries/SoftwareSerial/examples/TwoPortReceive/TwoPortReceive.ino
+++ b/libraries/SoftwareSerial/examples/TwoPortReceive/TwoPortReceive.ino
@@ -75,9 +75,3 @@ void loop() {
   // blank line to separate data from the two ports:
   Serial.println();
 }
-
-
-
-
-
-
diff --git a/libraries/SoftwareSerial/src/SoftwareSerial.cpp b/libraries/SoftwareSerial/src/SoftwareSerial.cpp
index 481218e406..09f1e65a77 100644
--- a/libraries/SoftwareSerial/src/SoftwareSerial.cpp
+++ b/libraries/SoftwareSerial/src/SoftwareSerial.cpp
@@ -34,17 +34,7 @@
 //
 // Includes
 //
-#include <stdint.h>
-#include <stdarg.h>
-
-#include <wiring_digital.h>
-#include <time.h>
-
-#include <Arduino.h>
 #include "SoftwareSerial.h"
-#include <HardwareTimer.h>
-#include <stm32_def.h>
-#include <digital_io.h>
 
 #define OVERSAMPLE 3 // in RX, Timer will generate interruption OVERSAMPLE time during a bit. Thus OVERSAMPLE ticks in a bit. (interrupt not synchonized with edge).
 
@@ -155,19 +145,16 @@ void SoftwareSerial::setSpeed(uint32_t speed)
 // one and returns true if it replaces another
 bool SoftwareSerial::listen()
 {
-  if (_receivePin >= 0) {
+  if (active_listener != this) {
     // wait for any transmit to complete as we may change speed
-    while (active_out)
-      ;
-    if (active_listener) {
-      active_listener->stopListening();
-    }
+    while (active_out);
+    active_listener->stopListening();
     rx_tick_cnt = 1; // 1 : next interrupt will decrease rx_tick_cnt to 0 which means RX pin level will be considered.
     rx_bit_cnt = -1; // rx_bit_cnt = -1 :  waiting for start bit
     setSpeed(_speed);
     active_listener = this;
     if (!_half_duplex) {
-      active_in = this;
+    active_in = this;
     }
     return true;
   }
@@ -179,8 +166,7 @@ bool SoftwareSerial::stopListening()
 {
   if (active_listener == this) {
     // wait for any output to complete
-    while (active_out)
-      ;
+    while (active_out);
     if (_half_duplex) {
       setRXTX(false);
     }
@@ -205,9 +191,7 @@ inline void SoftwareSerial::setTX()
 
 inline void SoftwareSerial::setRX()
 {
-  if (_receivePin > 0) {
-    pinMode(_receivePin, _inverse_logic ? INPUT_PULLDOWN : INPUT_PULLUP); // pullup for normal logic!
-  }
+  pinMode(_receivePin, _inverse_logic ? INPUT_PULLDOWN : INPUT_PULLUP); // pullup for normal logic!
 }
 
 inline void SoftwareSerial::setRXTX(bool input)
@@ -308,6 +292,7 @@ inline void SoftwareSerial::recv()
 /* static */
 inline void SoftwareSerial::handleInterrupt(HardwareTimer *timer)
 {
+  UNUSED(timer);
   if (active_in) {
     active_in->recv();
   }
@@ -333,9 +318,13 @@ SoftwareSerial::SoftwareSerial(uint16_t receivePin, uint16_t transmitPin, bool i
   _receive_buffer_tail(0),
   _receive_buffer_head(0)
 {
+  if ((receivePin < NUM_DIGITAL_PINS) || (transmitPin < NUM_DIGITAL_PINS)) {
   /* Enable GPIO clock for tx and rx pin*/
   set_GPIO_Port_Clock(STM_PORT(digitalPinToPinName(transmitPin)));
   set_GPIO_Port_Clock(STM_PORT(digitalPinToPinName(receivePin)));
+  } else {
+    _Error_Handler("ERROR: invalid pin number\n", -1);
+  }
 }
 
 //
diff --git a/libraries/SoftwareSerial/src/SoftwareSerial.h b/libraries/SoftwareSerial/src/SoftwareSerial.h
index fcd91342af..7ec0aee188 100644
--- a/libraries/SoftwareSerial/src/SoftwareSerial.h
+++ b/libraries/SoftwareSerial/src/SoftwareSerial.h
@@ -34,10 +34,6 @@
 #define SOFTWARESERIAL_H
 
 #include <Arduino.h>
-#include <stdint.h>
-#include <Stream.h>
-#include <Print.h>
-#include <HardwareTimer.h>
 
 /******************************************************************************
 * Definitions
@@ -125,13 +121,4 @@ class SoftwareSerial : public Stream {
     using Print::write;
 };
 
-// Arduino 0012 workaround
-#undef int
-#undef char
-#undef long
-#undef byte
-#undef float
-#undef abs
-#undef round
-
 #endif // SOFTWARESERIAL_H