diff --git a/include/PianoRoll.h b/include/PianoRoll.h
index 23fe7ddc6..25b4166c4 100644
--- a/include/PianoRoll.h
+++ b/include/PianoRoll.h
@@ -149,6 +149,8 @@ public:
 	{
 		return m_midiClip != nullptr;
 	}
+	
+	int trackOctaveSize() const;
 
 	Song::PlayModes desiredPlayModeForAccompany() const;
 
diff --git a/src/gui/editors/PianoRoll.cpp b/src/gui/editors/PianoRoll.cpp
index d4781eccd..b5a7e74b0 100644
--- a/src/gui/editors/PianoRoll.cpp
+++ b/src/gui/editors/PianoRoll.cpp
@@ -600,7 +600,7 @@ void PianoRoll::markSemiTone(int i, bool fromMenu)
 
 			const int first = chord->isScale() ? 0 : key;
 			const int last = chord->isScale() ? NumKeys : key + chord->last();
-			const int cap = ( chord->isScale() || chord->last() == 0 ) ? KeysPerOctave : chord->last();
+			const int cap = (chord->isScale() || chord->last() == 0) ? trackOctaveSize() : chord->last();
 
 			for( int i = first; i <= last; i++ )
 			{
@@ -937,6 +937,14 @@ void PianoRoll::hideMidiClip( MidiClip* clip )
 	}
 }
 
+
+int PianoRoll::trackOctaveSize() const
+{
+	auto ut = m_midiClip->instrumentTrack()->microtuner();
+	return ut->enabled() ? ut->octaveSize() : KeysPerOctave;
+}
+
+
 void PianoRoll::selectRegionFromPixels( int xStart, int xEnd )
 {
 
@@ -3950,7 +3958,8 @@ QList<int> PianoRoll::getAllOctavesForKey( int keyToMirror ) const
 {
 	QList<int> keys;
 
-	for (int i=keyToMirror % KeysPerOctave; i < NumKeys; i += KeysPerOctave)
+	int trackKeysPerOctave = trackOctaveSize();
+	for (int i = keyToMirror % trackKeysPerOctave; i < NumKeys; i += trackKeysPerOctave)
 	{
 		keys.append(i);
 	}