diff --git a/gtsam/nonlinear/NonlinearOptimizer.h b/gtsam/nonlinear/NonlinearOptimizer.h
index aec462889..3474ca1d2 100644
--- a/gtsam/nonlinear/NonlinearOptimizer.h
+++ b/gtsam/nonlinear/NonlinearOptimizer.h
@@ -27,6 +27,7 @@ namespace gtsam {
 class NullOptimizerWriter {
 public:
 	NullOptimizerWriter(double error) {}
+	virtual ~NullOptimizerWriter() {}
 	virtual void write(double error) {}
 };