diff --git a/gtsam/base/OptionalJacobian.h b/gtsam/base/OptionalJacobian.h
index 91cd1089a..5651816ba 100644
--- a/gtsam/base/OptionalJacobian.h
+++ b/gtsam/base/OptionalJacobian.h
@@ -108,6 +108,7 @@ public:
   }
 
   /// TODO: operator->()
+  Eigen::Map<Fixed>* operator->(){ return &map_; }
 };
 
 } // namespace gtsam