diff --git a/gtsam/nonlinear/lago.cpp b/gtsam/nonlinear/lago.cpp
index 5bb6f03f4..0f69f6ef0 100644
--- a/gtsam/nonlinear/lago.cpp
+++ b/gtsam/nonlinear/lago.cpp
@@ -35,7 +35,7 @@ static const Matrix I3 = eye(3);
 
 static const Key keyAnchor = symbol('Z', 9999999);
 static const noiseModel::Diagonal::shared_ptr priorOrientationNoise =
-    noiseModel::Diagonal::Variances((Vector(1) << 1e-8));
+    noiseModel::Diagonal::Sigmas((Vector(1) << 0));
 static const noiseModel::Diagonal::shared_ptr priorPose2Noise =
     noiseModel::Diagonal::Variances((Vector(3) << 1e-6, 1e-6, 1e-8));