diff --git a/gtsam/linear/NoiseModel.h b/gtsam/linear/NoiseModel.h
index 7d95d9276..04c26336f 100644
--- a/gtsam/linear/NoiseModel.h
+++ b/gtsam/linear/NoiseModel.h
@@ -870,7 +870,6 @@ namespace gtsam {
   typedef noiseModel::Gaussian::shared_ptr SharedGaussian;
   typedef noiseModel::Diagonal::shared_ptr SharedDiagonal;
   typedef noiseModel::Constrained::shared_ptr SharedConstrained;
-  typedef noiseModel::Isotropic::shared_ptr SharedIsotropic;
 
 } // namespace gtsam