diff --git a/gtsam/slam/SmartProjectionFactor.h b/gtsam/slam/SmartProjectionFactor.h
index 698d8771f..2bfcbfaa0 100644
--- a/gtsam/slam/SmartProjectionFactor.h
+++ b/gtsam/slam/SmartProjectionFactor.h
@@ -104,7 +104,7 @@ protected:
   /// shorthand for this class
   typedef SmartProjectionFactor<POSE, CALIBRATION, D> This;
 
-  static const int ZDim = traits_x<Point2>::dimension;    ///< Measurement dimension
+  static const int ZDim = 2;    ///< Measurement dimension
 
 public:
 
diff --git a/gtsam_unstable/slam/SmartStereoProjectionFactor.h b/gtsam_unstable/slam/SmartStereoProjectionFactor.h
index c05407d2f..548bc98a0 100644
--- a/gtsam_unstable/slam/SmartStereoProjectionFactor.h
+++ b/gtsam_unstable/slam/SmartStereoProjectionFactor.h
@@ -107,7 +107,7 @@ protected:
   /// shorthand for this class
   typedef SmartStereoProjectionFactor<POSE, LANDMARK, CALIBRATION, D> This;
 
-  enum {ZDim = traits_x<gtsam::StereoPoint2>::dimension};    ///< Dimension trait of measurement type
+  enum {ZDim = 3};    ///< Dimension trait of measurement type
 
 public: