diff --git a/stepmania/src/NoteField.cpp b/stepmania/src/NoteField.cpp
index 215ecd188b..9fd2b2ce11 100644
--- a/stepmania/src/NoteField.cpp
+++ b/stepmania/src/NoteField.cpp
@@ -124,6 +124,7 @@ void NoteField::Load(
 	int iFirstPixelToDraw, 
 	int iLastPixelToDraw )
 {
+	ASSERT( pNoteData );
 	m_pNoteData = pNoteData;
 	m_iStartDrawingPixel = iFirstPixelToDraw;
 	m_iEndDrawingPixel = iLastPixelToDraw;