diff --git a/gtsam/slam/TriangulationFactor.h b/gtsam/slam/TriangulationFactor.h
index 32aa590a6..3b8486a59 100644
--- a/gtsam/slam/TriangulationFactor.h
+++ b/gtsam/slam/TriangulationFactor.h
@@ -34,6 +34,8 @@ public:
 
   /// CAMERA type
   using Camera = CAMERA;
+  /// shorthand for measurement type, e.g. Point2 or StereoPoint2
+  using Measurement = typename CAMERA::Measurement;
 
 protected:
 
@@ -43,9 +45,6 @@ protected:
   /// shorthand for this class
   using This = TriangulationFactor<CAMERA>;
 
-  /// shorthand for measurement type, e.g. Point2 or StereoPoint2
-  using Measurement = typename CAMERA::Measurement;
-
   // Keep a copy of measurement and calibration for I/O
   const CAMERA camera_; ///< CAMERA in which this landmark was seen
   const Measurement measured_; ///< 2D measurement