diff --git a/gtsam/nonlinear/NonlinearFactorGraph.h b/gtsam/nonlinear/NonlinearFactorGraph.h
index c7f10475a..2cea72e7e 100644
--- a/gtsam/nonlinear/NonlinearFactorGraph.h
+++ b/gtsam/nonlinear/NonlinearFactorGraph.h
@@ -58,7 +58,7 @@ namespace gtsam {
 
 		template<class F>
 		void add(const F& factor) {
-			push_back(boost::shared_ptr<F>(new F(factor)));
+			this->push_back(boost::shared_ptr<F>(new F(factor)));
 		}
 
 		/**