diff --git a/gtsam/navigation/CombinedImuFactor.h b/gtsam/navigation/CombinedImuFactor.h
index 6eb4de58b..d2ad32122 100644
--- a/gtsam/navigation/CombinedImuFactor.h
+++ b/gtsam/navigation/CombinedImuFactor.h
@@ -218,7 +218,7 @@ public:
       const Vector3& omegaCoriolis, const bool use2ndOrderCoriolis = false,
       boost::optional<Vector3&> deltaPij_biascorrected_out = boost::none,
       boost::optional<Vector3&> deltaVij_biascorrected_out = boost::none) {
-	  PoseVelocityBias PVB(PIM.Predict(pose_i, vel_i, bias_i, gravity, omegaCoriolis, use2ndOrderCoriolis, deltaPij_biascorrected_out, deltaVij_biascorrected_out));
+	  PoseVelocityBias PVB(PIM.predict(pose_i, vel_i, bias_i, gravity, omegaCoriolis, use2ndOrderCoriolis, deltaPij_biascorrected_out, deltaVij_biascorrected_out));
 	  pose_j = PVB.pose;
 	  vel_j = PVB.velocity;
   }
diff --git a/gtsam/navigation/ImuFactor.h b/gtsam/navigation/ImuFactor.h
index 4369a411f..984d62d08 100644
--- a/gtsam/navigation/ImuFactor.h
+++ b/gtsam/navigation/ImuFactor.h
@@ -200,7 +200,7 @@ public:
       const Vector3& omegaCoriolis, const bool use2ndOrderCoriolis = false,
       boost::optional<Vector3&> deltaPij_biascorrected_out = boost::none,
       boost::optional<Vector3&> deltaVij_biascorrected_out = boost::none) {
-	  PoseVelocityBias PVB(PIM.Predict(pose_i, vel_i, bias_i, gravity, omegaCoriolis, use2ndOrderCoriolis, deltaPij_biascorrected_out, deltaVij_biascorrected_out));
+	  PoseVelocityBias PVB(PIM.predict(pose_i, vel_i, bias_i, gravity, omegaCoriolis, use2ndOrderCoriolis, deltaPij_biascorrected_out, deltaVij_biascorrected_out));
 	  pose_j = PVB.pose;
 	  vel_j = PVB.velocity;
   }
diff --git a/gtsam/navigation/PreintegrationBase.h b/gtsam/navigation/PreintegrationBase.h
index 3c30082f6..29b9b6e66 100644
--- a/gtsam/navigation/PreintegrationBase.h
+++ b/gtsam/navigation/PreintegrationBase.h
@@ -199,7 +199,7 @@ public:
 
   /// Predict state at time j
   //------------------------------------------------------------------------------
-  PoseVelocityBias Predict(const Pose3& pose_i, const Vector3& vel_i,
+  PoseVelocityBias predict(const Pose3& pose_i, const Vector3& vel_i,
       const imuBias::ConstantBias& bias_i, const Vector3& gravity,
       const Vector3& omegaCoriolis, const bool use2ndOrderCoriolis = false,
       boost::optional<Vector3&> deltaPij_biascorrected_out = boost::none,
@@ -273,7 +273,7 @@ public:
     // Evaluate residual error, according to [3]
     /* ---------------------------------------------------------------------------------------------------- */
     Vector3 deltaPij_biascorrected, deltaVij_biascorrected;
-    PoseVelocityBias predictedState_j = Predict(pose_i, vel_i, bias_i, gravity,
+    PoseVelocityBias predictedState_j = predict(pose_i, vel_i, bias_i, gravity,
         omegaCoriolis, use2ndOrderCoriolis, deltaPij_biascorrected, deltaVij_biascorrected);
 
     // Ri.transpose() is important here to preserve a model with *additive* Gaussian noise of correct covariance
diff --git a/gtsam/navigation/tests/testCombinedImuFactor.cpp b/gtsam/navigation/tests/testCombinedImuFactor.cpp
index 70686acfd..c6eb1396e 100644
--- a/gtsam/navigation/tests/testCombinedImuFactor.cpp
+++ b/gtsam/navigation/tests/testCombinedImuFactor.cpp
@@ -294,7 +294,7 @@ TEST(CombinedImuFactor, PredictPositionAndVelocity){
   // Predict
   Pose3 x1;
   Vector3 v1(0, 0.0, 0.0);
-  PoseVelocityBias poseVelocityBias = Combined_pre_int_data.Predict(x1, v1, bias, gravity, omegaCoriolis);
+  PoseVelocityBias poseVelocityBias = Combined_pre_int_data.predict(x1, v1, bias, gravity, omegaCoriolis);
   Pose3 expectedPose(Rot3(), Point3(0, 0.5, 0));
   Vector3 expectedVelocity; expectedVelocity<<0,1,0;
   EXPECT(assert_equal(expectedPose, poseVelocityBias.pose));
diff --git a/gtsam/navigation/tests/testImuFactor.cpp b/gtsam/navigation/tests/testImuFactor.cpp
index b1dbd504f..62f496894 100644
--- a/gtsam/navigation/tests/testImuFactor.cpp
+++ b/gtsam/navigation/tests/testImuFactor.cpp
@@ -883,7 +883,7 @@ TEST(ImuFactor, PredictPositionAndVelocity){
     // Predict
     Pose3 x1;
     Vector3 v1(0, 0.0, 0.0);
-    PoseVelocityBias poseVelocity = pre_int_data.Predict(x1, v1, bias, gravity, omegaCoriolis);
+    PoseVelocityBias poseVelocity = pre_int_data.predict(x1, v1, bias, gravity, omegaCoriolis);
     Pose3 expectedPose(Rot3(), Point3(0, 0.5, 0));
     Vector3 expectedVelocity; expectedVelocity<<0,1,0;
     EXPECT(assert_equal(expectedPose, poseVelocity.pose));