diff --git a/examples/LIEKF_NavstateExample.cpp b/examples/LIEKF_NavstateExample.cpp
index 250d5cda8..9798dca02 100644
--- a/examples/LIEKF_NavstateExample.cpp
+++ b/examples/LIEKF_NavstateExample.cpp
@@ -31,7 +31,7 @@ using namespace gtsam;
  * @param imu  6×1 vector [a; ω]: linear acceleration and angular velocity.
  * @return     9×1 tangent: [ω; 0₃; a].
  */
-Vector9 dynamics(const Vector6& imu, OptionalJacobian<9, 9> H = {}) {
+Vector9 dynamics(const Vector6& imu) {
   auto a = imu.head<3>();
   auto w = imu.tail<3>();
   Vector9 xi;
diff --git a/examples/LIEKF_Rot3Example.cpp b/examples/LIEKF_Rot3Example.cpp
index 331c01bb1..172af894d 100644
--- a/examples/LIEKF_Rot3Example.cpp
+++ b/examples/LIEKF_Rot3Example.cpp
@@ -32,14 +32,14 @@ using namespace gtsam;
 static constexpr double k = 0.5;
 Vector3 dynamicsSO3(const Rot3& X, OptionalJacobian<3, 3> H = {}) {
   // φ = Logmap(R), Dφ = ∂φ/∂δR
-  Matrix3 Dφ;
-  Vector3 φ = Rot3::Logmap(X, Dφ);
+  Matrix3 D_phi;
+  Vector3 phi = Rot3::Logmap(X, D_phi);
   // zero out yaw
-  φ[2] = 0.0;
-  Dφ.row(2).setZero();
+  phi[2] = 0.0;
+  D_phi.row(2).setZero();
 
-  if (H) *H = -k * Dφ;  // ∂(–kφ)/∂δR
-  return -k * φ;        // xi ∈ 𝔰𝔬(3)
+  if (H) *H = -k * D_phi;  // ∂(–kφ)/∂δR
+  return -k * phi;        // xi ∈ 𝔰𝔬(3)
 }
 
 // --- 2) Magnetometer model: z = R⁻¹ m, H = –[z]_× ---
diff --git a/examples/LIEKF_SE2_SimpleGPSExample.cpp b/examples/LIEKF_SE2_SimpleGPSExample.cpp
index ecef67cf7..0985d2372 100644
--- a/examples/LIEKF_SE2_SimpleGPSExample.cpp
+++ b/examples/LIEKF_SE2_SimpleGPSExample.cpp
@@ -58,7 +58,7 @@ int main() {
 
   // Define the process covariance and measurement covariance matrices Q and R.
   Matrix3 Q = (Vector3(0.05, 0.05, 0.001)).asDiagonal();
-  Matrix2 R = (Vector2(0.01, 0.01)).asDiagonal();
+  Matrix2 R = I_2x2 * 0.01;
 
   // Define odometry movements.
   // U1: Move 1 unit in X, 1 unit in Y, 0.5 radians in theta.