diff --git a/src/serialmididevice.cpp b/src/serialmididevice.cpp
index 883fd4d..b37a498 100644
--- a/src/serialmididevice.cpp
+++ b/src/serialmididevice.cpp
@@ -28,11 +28,15 @@
 
 LOGMODULE("serialmididevice");
 
+// There are several UART options - see circle/include/serial.h
+// 0 corresponds to GP14/GP15 on all RPi versions.
+#define SERIAL_MIDI_DEVICE 0
+
 CSerialMIDIDevice::CSerialMIDIDevice (CMiniDexed *pSynthesizer, CInterruptSystem *pInterrupt,
 				      CConfig *pConfig, CUserInterface *pUI)
 :	CMIDIDevice (pSynthesizer, pConfig, pUI),
 	m_pConfig (pConfig),
-	m_Serial (pInterrupt, TRUE),
+	m_Serial (pInterrupt, TRUE, SERIAL_MIDI_DEVICE),
 	m_nSerialState (0),
 	m_nSysEx (0),
 	m_SendBuffer (&m_Serial)