diff --git a/Auto485.cpp b/Auto485.cpp
index 53c86be..fff3f1a 100644
--- a/Auto485.cpp
+++ b/Auto485.cpp
@@ -29,12 +29,18 @@
 Auto485::Auto485(int DE_pin, int RE_pin, HardwareSerial &serial_port)
 : _DE_pin(DE_pin)
 , _RE_pin(RE_pin == -1 ? DE_pin : RE_pin)
-, _serial(serial_port)
+, _pins_initialized(false)
 , _mode(RX)
+, _serial(serial_port)
+{
+}
+
+void Auto485::init_pins(void)
 {
 	pinMode(_DE_pin, OUTPUT); // defaults to LOW = read mode
 	if (_DE_pin != _RE_pin)
 		pinMode(_RE_pin, OUTPUT); // defaults to LOW = read mode
+	_pins_initialized = true;
 }
 
 void Auto485::set_mode(enum Mode mode)
@@ -50,11 +56,15 @@ void Auto485::set_mode(enum Mode mode)
 
 void Auto485::begin(unsigned long baud)
 {
+	if (!_pins_initialized)
+		init_pins();
 	_serial.begin(baud);
 }
 
 void Auto485::begin(unsigned long baud, uint8_t config)
 {
+	if (!_pins_initialized)
+		init_pins();
 	_serial.begin(baud, config);
 }
 
diff --git a/Auto485.h b/Auto485.h
index 110af8a..e5823a1 100644
--- a/Auto485.h
+++ b/Auto485.h
@@ -63,8 +63,10 @@ class Auto485 : public Stream
 		using   Print::println;
 		
 private:
+		void    init_pins(void);
 		int     _DE_pin;
 		int     _RE_pin;
+		bool    _pins_initialized;
 		enum    Mode _mode;
 		HardwareSerial& _serial;
 };