diff --git a/cpp/Lie-inl.h b/cpp/Lie-inl.h
index 7e3b1ecbe..b2ae16dec 100644
--- a/cpp/Lie-inl.h
+++ b/cpp/Lie-inl.h
@@ -24,6 +24,7 @@ namespace gtsam {
 
   /**
    * Returns Exponential mapy
+   * This is for matlab wrapper
    */
   template<class T>
   T Lie<T>::expmap(const Vector& v) const {