diff --git a/LEGO1/realtime/matrix.h b/LEGO1/realtime/matrix.h
index e5653650..4f65e50b 100644
--- a/LEGO1/realtime/matrix.h
+++ b/LEGO1/realtime/matrix.h
@@ -68,6 +68,7 @@ class Matrix4Impl {
 	inline float& operator[](size_t idx) { return ((float*) m_data)[idx]; }
 
 protected:
+	// TODO: Currently unclear whether this class contains a Matrix4* or float*.
 	Matrix4* m_data;
 };