diff --git a/gtsam_unstable/gtsam_unstable.h b/gtsam_unstable/gtsam_unstable.h
index 7ccde30a4..d87e71048 100644
--- a/gtsam_unstable/gtsam_unstable.h
+++ b/gtsam_unstable/gtsam_unstable.h
@@ -388,7 +388,7 @@ virtual class SmartRangeFactor : gtsam::NoiseModelFactor {
 //
 //  // enabling serialization functionality
 //  void serialize() const;
-};
+//};
 
 
 #include <gtsam/slam/RangeFactor.h>