diff --git a/Firmware/Sd2PinMap.h b/Firmware/Sd2PinMap.h
index 8a608731..da50958f 100644
--- a/Firmware/Sd2PinMap.h
+++ b/Firmware/Sd2PinMap.h
@@ -37,10 +37,6 @@ struct pin_map_t {
 || defined(__AVR_ATmega2560__)
 // Mega
 
-// Two Wire (aka I2C) ports
-uint8_t const SDA_PIN = 20;  // D1
-uint8_t const SCL_PIN = 21;  // D0
-
 #undef MOSI_PIN
 #undef MISO_PIN
 // SPI port
@@ -365,4 +361,4 @@ static inline __attribute__((always_inline))
 #endif  // Sd2PinMap_h
 
 
-#endif
\ No newline at end of file
+#endif
diff --git a/Firmware/pins.h b/Firmware/pins.h
index 5d3b4f83..1c20a001 100644
--- a/Firmware/pins.h
+++ b/Firmware/pins.h
@@ -25,6 +25,11 @@
 #error Unknown MOTHERBOARD value in configuration.h
 #endif
 
+#if !defined(SDA_PIN) && (defined(__AVR_ATmega1280__) || defined(__AVR_ATmega2560__))
+#define SDA_PIN 20
+#define SCL_PIN 21
+#endif
+
 //List of pins which to ignore when asked to change by gcode, 0 and 1 are RX and TX, do not mess with those!
 #define _E0_PINS E0_STEP_PIN, E0_DIR_PIN, E0_ENABLE_PIN, HEATER_0_PIN,
 #if EXTRUDERS > 1