diff --git a/cartographer/cloud/internal/map_builder_context.cc b/cartographer/cloud/internal/map_builder_context.cc
index 1daae11..3437196 100644
--- a/cartographer/cloud/internal/map_builder_context.cc
+++ b/cartographer/cloud/internal/map_builder_context.cc
@@ -17,8 +17,8 @@
 #include "cartographer/cloud/internal/map_builder_context.h"
 
 #include "cartographer/cloud/internal/map_builder_server.h"
-#include "cartographer/mapping/2d/local_slam_result_2d.h"
-#include "cartographer/mapping/3d/local_slam_result_3d.h"
+#include "cartographer/mapping/internal/2d/local_slam_result_2d.h"
+#include "cartographer/mapping/internal/3d/local_slam_result_3d.h"
 
 namespace cartographer {
 namespace cloud {
diff --git a/cartographer/mapping/2d/range_data_inserter_2d.cc b/cartographer/mapping/2d/range_data_inserter_2d.cc
index 387d2e0..6e2dc0d 100644
--- a/cartographer/mapping/2d/range_data_inserter_2d.cc
+++ b/cartographer/mapping/2d/range_data_inserter_2d.cc
@@ -20,8 +20,8 @@
 
 #include "Eigen/Core"
 #include "Eigen/Geometry"
-#include "cartographer/mapping/2d/ray_casting.h"
 #include "cartographer/mapping/2d/xy_index.h"
+#include "cartographer/mapping/internal/2d/ray_casting.h"
 #include "cartographer/mapping/probability_values.h"
 #include "glog/logging.h"
 
diff --git a/cartographer/mapping/3d/scan_matching/ceres_scan_matcher_3d.cc b/cartographer/mapping/3d/scan_matching/ceres_scan_matcher_3d.cc
index 366f314..16353e6 100644
--- a/cartographer/mapping/3d/scan_matching/ceres_scan_matcher_3d.cc
+++ b/cartographer/mapping/3d/scan_matching/ceres_scan_matcher_3d.cc
@@ -22,9 +22,9 @@
 
 #include "cartographer/common/ceres_solver_options.h"
 #include "cartographer/common/make_unique.h"
-#include "cartographer/mapping/3d/rotation_parameterization.h"
 #include "cartographer/mapping/3d/scan_matching/rotation_delta_cost_functor_3d.h"
 #include "cartographer/mapping/3d/scan_matching/translation_delta_cost_functor_3d.h"
+#include "cartographer/mapping/internal/3d/rotation_parameterization.h"
 #include "cartographer/mapping/internal/3d/scan_matching/occupied_space_cost_function_3d.h"
 #include "cartographer/mapping/pose_graph/ceres_pose.h"
 #include "cartographer/transform/rigid_transform.h"
diff --git a/cartographer/mapping/2d/local_slam_result_2d.cc b/cartographer/mapping/internal/2d/local_slam_result_2d.cc
similarity index 90%
rename from cartographer/mapping/2d/local_slam_result_2d.cc
rename to cartographer/mapping/internal/2d/local_slam_result_2d.cc
index 4469379..5de112f 100644
--- a/cartographer/mapping/2d/local_slam_result_2d.cc
+++ b/cartographer/mapping/internal/2d/local_slam_result_2d.cc
@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping/2d/local_slam_result_2d.h"
-#include "cartographer/mapping/2d/pose_graph_2d.h"
+#include "cartographer/mapping/internal/2d/local_slam_result_2d.h"
+#include "cartographer/mapping/internal/2d/pose_graph_2d.h"
 
 namespace cartographer {
 namespace mapping {
diff --git a/cartographer/mapping/2d/local_slam_result_2d.h b/cartographer/mapping/internal/2d/local_slam_result_2d.h
similarity index 89%
rename from cartographer/mapping/2d/local_slam_result_2d.h
rename to cartographer/mapping/internal/2d/local_slam_result_2d.h
index 6cf007f..ae0fd38 100644
--- a/cartographer/mapping/2d/local_slam_result_2d.h
+++ b/cartographer/mapping/internal/2d/local_slam_result_2d.h
@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-#ifndef CARTOGRAPHER_MAPPING_2D_LOCAL_SLAM_RESULT_2D_H_
-#define CARTOGRAPHER_MAPPING_2D_LOCAL_SLAM_RESULT_2D_H_
+#ifndef CARTOGRAPHER_MAPPING_INTERNAL_2D_LOCAL_SLAM_RESULT_2D_H_
+#define CARTOGRAPHER_MAPPING_INTERNAL_2D_LOCAL_SLAM_RESULT_2D_H_
 
 #include "cartographer/mapping/2d/submap_2d.h"
 #include "cartographer/mapping/local_slam_result_data.h"
@@ -46,4 +46,4 @@ class LocalSlamResult2D : public LocalSlamResultData {
 }  // namespace mapping
 }  // namespace cartographer
 
-#endif  // CARTOGRAPHER_MAPPING_2D_LOCAL_SLAM_RESULT_2D_H_
+#endif  // CARTOGRAPHER_MAPPING_INTERNAL_2D_LOCAL_SLAM_RESULT_2D_H_
diff --git a/cartographer/mapping/2d/local_trajectory_builder_options_2d.cc b/cartographer/mapping/internal/2d/local_trajectory_builder_options_2d.cc
similarity index 97%
rename from cartographer/mapping/2d/local_trajectory_builder_options_2d.cc
rename to cartographer/mapping/internal/2d/local_trajectory_builder_options_2d.cc
index 0a590f5..88f6401 100644
--- a/cartographer/mapping/2d/local_trajectory_builder_options_2d.cc
+++ b/cartographer/mapping/internal/2d/local_trajectory_builder_options_2d.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping/2d/local_trajectory_builder_options_2d.h"
+#include "cartographer/mapping/internal/2d/local_trajectory_builder_options_2d.h"
 
 #include "cartographer/mapping/2d/scan_matching/ceres_scan_matcher_2d.h"
 #include "cartographer/mapping/2d/scan_matching/real_time_correlative_scan_matcher_2d.h"
diff --git a/cartographer/mapping/2d/local_trajectory_builder_options_2d.h b/cartographer/mapping/internal/2d/local_trajectory_builder_options_2d.h
similarity index 80%
rename from cartographer/mapping/2d/local_trajectory_builder_options_2d.h
rename to cartographer/mapping/internal/2d/local_trajectory_builder_options_2d.h
index d66337e..4b52e65 100644
--- a/cartographer/mapping/2d/local_trajectory_builder_options_2d.h
+++ b/cartographer/mapping/internal/2d/local_trajectory_builder_options_2d.h
@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-#ifndef CARTOGRAPHER_MAPPING_2D_LOCAL_TRAJECTORY_BUILDER_OPTIONS_2D_H_
-#define CARTOGRAPHER_MAPPING_2D_LOCAL_TRAJECTORY_BUILDER_OPTIONS_2D_H_
+#ifndef CARTOGRAPHER_MAPPING_INTERNAL_2D_LOCAL_TRAJECTORY_BUILDER_OPTIONS_2D_H_
+#define CARTOGRAPHER_MAPPING_INTERNAL_2D_LOCAL_TRAJECTORY_BUILDER_OPTIONS_2D_H_
 
 #include "cartographer/common/lua_parameter_dictionary.h"
 #include "cartographer/mapping/2d/proto/local_trajectory_builder_options_2d.pb.h"
@@ -29,4 +29,4 @@ proto::LocalTrajectoryBuilderOptions2D CreateLocalTrajectoryBuilderOptions2D(
 }  // namespace mapping
 }  // namespace cartographer
 
-#endif  // CARTOGRAPHER_MAPPING_2D_LOCAL_TRAJECTORY_BUILDER_OPTIONS_2D_H_
+#endif  // CARTOGRAPHER_MAPPING_INTERNAL_2D_LOCAL_TRAJECTORY_BUILDER_OPTIONS_2D_H_
diff --git a/cartographer/mapping/2d/pose_graph/constraint_builder_2d.cc b/cartographer/mapping/internal/2d/pose_graph/constraint_builder_2d.cc
similarity index 99%
rename from cartographer/mapping/2d/pose_graph/constraint_builder_2d.cc
rename to cartographer/mapping/internal/2d/pose_graph/constraint_builder_2d.cc
index 91982b0..c6445d0 100644
--- a/cartographer/mapping/2d/pose_graph/constraint_builder_2d.cc
+++ b/cartographer/mapping/internal/2d/pose_graph/constraint_builder_2d.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping/2d/pose_graph/constraint_builder_2d.h"
+#include "cartographer/mapping/internal/2d/pose_graph/constraint_builder_2d.h"
 
 #include <cmath>
 #include <functional>
diff --git a/cartographer/mapping/2d/pose_graph/constraint_builder_2d.h b/cartographer/mapping/internal/2d/pose_graph/constraint_builder_2d.h
similarity index 96%
rename from cartographer/mapping/2d/pose_graph/constraint_builder_2d.h
rename to cartographer/mapping/internal/2d/pose_graph/constraint_builder_2d.h
index c671be1..f0bf205 100644
--- a/cartographer/mapping/2d/pose_graph/constraint_builder_2d.h
+++ b/cartographer/mapping/internal/2d/pose_graph/constraint_builder_2d.h
@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-#ifndef CARTOGRAPHER_MAPPING_2D_POSE_GRAPH_CONSTRAINT_BUILDER_2D_H_
-#define CARTOGRAPHER_MAPPING_2D_POSE_GRAPH_CONSTRAINT_BUILDER_2D_H_
+#ifndef CARTOGRAPHER_MAPPING_INTERNAL_2D_POSE_GRAPH_CONSTRAINT_BUILDER_2D_H_
+#define CARTOGRAPHER_MAPPING_INTERNAL_2D_POSE_GRAPH_CONSTRAINT_BUILDER_2D_H_
 
 #include <array>
 #include <deque>
@@ -181,4 +181,4 @@ class ConstraintBuilder2D {
 }  // namespace mapping
 }  // namespace cartographer
 
-#endif  // CARTOGRAPHER_MAPPING_2D_POSE_GRAPH_CONSTRAINT_BUILDER_2D_H_
+#endif  // CARTOGRAPHER_MAPPING_INTERNAL_2D_POSE_GRAPH_CONSTRAINT_BUILDER_2D_H_
diff --git a/cartographer/mapping/2d/pose_graph/landmark_cost_function_2d.h b/cartographer/mapping/internal/2d/pose_graph/landmark_cost_function_2d.h
similarity index 94%
rename from cartographer/mapping/2d/pose_graph/landmark_cost_function_2d.h
rename to cartographer/mapping/internal/2d/pose_graph/landmark_cost_function_2d.h
index 17d6966..3b7eeda 100644
--- a/cartographer/mapping/2d/pose_graph/landmark_cost_function_2d.h
+++ b/cartographer/mapping/internal/2d/pose_graph/landmark_cost_function_2d.h
@@ -14,12 +14,12 @@
  * limitations under the License.
  */
 
-#ifndef CARTOGRAPHER_MAPPING_2D_POSE_GRAPH_LANDMARK_COST_FUNCTION_2D_H_
-#define CARTOGRAPHER_MAPPING_2D_POSE_GRAPH_LANDMARK_COST_FUNCTION_2D_H_
+#ifndef CARTOGRAPHER_MAPPING_INTERNAL_2D_POSE_GRAPH_LANDMARK_COST_FUNCTION_2D_H_
+#define CARTOGRAPHER_MAPPING_INTERNAL_2D_POSE_GRAPH_LANDMARK_COST_FUNCTION_2D_H_
 
 #include "Eigen/Core"
 #include "Eigen/Geometry"
-#include "cartographer/mapping/2d/pose_graph/optimization_problem_2d.h"
+#include "cartographer/mapping/internal/2d/pose_graph/optimization_problem_2d.h"
 #include "cartographer/mapping/pose_graph/cost_helpers.h"
 #include "cartographer/mapping/pose_graph_interface.h"
 #include "cartographer/transform/rigid_transform.h"
@@ -124,4 +124,4 @@ class LandmarkCostFunction2D {
 }  // namespace mapping
 }  // namespace cartographer
 
-#endif  // CARTOGRAPHER_MAPPING_2D_POSE_GRAPH_LANDMARK_COST_FUNCTION_2D_H_
+#endif  // CARTOGRAPHER_MAPPING_INTERNAL_2D_POSE_GRAPH_LANDMARK_COST_FUNCTION_2D_H_
diff --git a/cartographer/mapping/2d/pose_graph/landmark_cost_function_2d_test.cc b/cartographer/mapping/internal/2d/pose_graph/landmark_cost_function_2d_test.cc
similarity index 97%
rename from cartographer/mapping/2d/pose_graph/landmark_cost_function_2d_test.cc
rename to cartographer/mapping/internal/2d/pose_graph/landmark_cost_function_2d_test.cc
index 123e4c9..c8de26c 100644
--- a/cartographer/mapping/2d/pose_graph/landmark_cost_function_2d_test.cc
+++ b/cartographer/mapping/internal/2d/pose_graph/landmark_cost_function_2d_test.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping/2d/pose_graph/landmark_cost_function_2d.h"
+#include "cartographer/mapping/internal/2d/pose_graph/landmark_cost_function_2d.h"
 
 #include <memory>
 
diff --git a/cartographer/mapping/2d/pose_graph/optimization_problem_2d.cc b/cartographer/mapping/internal/2d/pose_graph/optimization_problem_2d.cc
similarity index 98%
rename from cartographer/mapping/2d/pose_graph/optimization_problem_2d.cc
rename to cartographer/mapping/internal/2d/pose_graph/optimization_problem_2d.cc
index 4b5b72b..2c8d5a8 100644
--- a/cartographer/mapping/2d/pose_graph/optimization_problem_2d.cc
+++ b/cartographer/mapping/internal/2d/pose_graph/optimization_problem_2d.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping/2d/pose_graph/optimization_problem_2d.h"
+#include "cartographer/mapping/internal/2d/pose_graph/optimization_problem_2d.h"
 
 #include <algorithm>
 #include <array>
@@ -27,8 +27,8 @@
 #include "cartographer/common/ceres_solver_options.h"
 #include "cartographer/common/histogram.h"
 #include "cartographer/common/math.h"
-#include "cartographer/mapping/2d/pose_graph/landmark_cost_function_2d.h"
-#include "cartographer/mapping/2d/pose_graph/spa_cost_function_2d.h"
+#include "cartographer/mapping/internal/2d/pose_graph/landmark_cost_function_2d.h"
+#include "cartographer/mapping/internal/2d/pose_graph/spa_cost_function_2d.h"
 #include "cartographer/mapping/pose_graph/ceres_pose.h"
 #include "cartographer/sensor/odometry_data.h"
 #include "cartographer/transform/transform.h"
diff --git a/cartographer/mapping/2d/pose_graph/optimization_problem_2d.h b/cartographer/mapping/internal/2d/pose_graph/optimization_problem_2d.h
similarity index 94%
rename from cartographer/mapping/2d/pose_graph/optimization_problem_2d.h
rename to cartographer/mapping/internal/2d/pose_graph/optimization_problem_2d.h
index cace99d..ef3e484 100644
--- a/cartographer/mapping/2d/pose_graph/optimization_problem_2d.h
+++ b/cartographer/mapping/internal/2d/pose_graph/optimization_problem_2d.h
@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-#ifndef CARTOGRAPHER_MAPPING_2D_POSE_GRAPH_OPTIMIZATION_PROBLEM_2D_H_
-#define CARTOGRAPHER_MAPPING_2D_POSE_GRAPH_OPTIMIZATION_PROBLEM_2D_H_
+#ifndef CARTOGRAPHER_MAPPING_INTERNAL_2D_POSE_GRAPH_OPTIMIZATION_PROBLEM_2D_H_
+#define CARTOGRAPHER_MAPPING_INTERNAL_2D_POSE_GRAPH_OPTIMIZATION_PROBLEM_2D_H_
 
 #include <array>
 #include <deque>
@@ -114,4 +114,4 @@ class OptimizationProblem2D {
 }  // namespace mapping
 }  // namespace cartographer
 
-#endif  // CARTOGRAPHER_MAPPING_2D_POSE_GRAPH_OPTIMIZATION_PROBLEM_2D_H_
+#endif  // CARTOGRAPHER_MAPPING_INTERNAL_2D_POSE_GRAPH_OPTIMIZATION_PROBLEM_2D_H_
diff --git a/cartographer/mapping/2d/pose_graph/spa_cost_function_2d.h b/cartographer/mapping/internal/2d/pose_graph/spa_cost_function_2d.h
similarity index 90%
rename from cartographer/mapping/2d/pose_graph/spa_cost_function_2d.h
rename to cartographer/mapping/internal/2d/pose_graph/spa_cost_function_2d.h
index bb80284..75456a2 100644
--- a/cartographer/mapping/2d/pose_graph/spa_cost_function_2d.h
+++ b/cartographer/mapping/internal/2d/pose_graph/spa_cost_function_2d.h
@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-#ifndef CARTOGRAPHER_MAPPING_2D_POSE_GRAPH_SPA_COST_FUNCTION_2D_H_
-#define CARTOGRAPHER_MAPPING_2D_POSE_GRAPH_SPA_COST_FUNCTION_2D_H_
+#ifndef CARTOGRAPHER_MAPPING_INTERNAL_2D_POSE_GRAPH_SPA_COST_FUNCTION_2D_H_
+#define CARTOGRAPHER_MAPPING_INTERNAL_2D_POSE_GRAPH_SPA_COST_FUNCTION_2D_H_
 
 #include <array>
 
@@ -66,4 +66,4 @@ class SpaCostFunction2D {
 }  // namespace mapping
 }  // namespace cartographer
 
-#endif  // CARTOGRAPHER_MAPPING_2D_POSE_GRAPH_SPA_COST_FUNCTION_2D_H_
+#endif  // CARTOGRAPHER_MAPPING_INTERNAL_2D_POSE_GRAPH_SPA_COST_FUNCTION_2D_H_
diff --git a/cartographer/mapping/2d/pose_graph_2d.cc b/cartographer/mapping/internal/2d/pose_graph_2d.cc
similarity index 99%
rename from cartographer/mapping/2d/pose_graph_2d.cc
rename to cartographer/mapping/internal/2d/pose_graph_2d.cc
index d8f1146..c910930 100644
--- a/cartographer/mapping/2d/pose_graph_2d.cc
+++ b/cartographer/mapping/internal/2d/pose_graph_2d.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping/2d/pose_graph_2d.h"
+#include "cartographer/mapping/internal/2d/pose_graph_2d.h"
 
 #include <algorithm>
 #include <cmath>
diff --git a/cartographer/mapping/2d/pose_graph_2d.h b/cartographer/mapping/internal/2d/pose_graph_2d.h
similarity index 97%
rename from cartographer/mapping/2d/pose_graph_2d.h
rename to cartographer/mapping/internal/2d/pose_graph_2d.h
index b69222d..3f34e17 100644
--- a/cartographer/mapping/2d/pose_graph_2d.h
+++ b/cartographer/mapping/internal/2d/pose_graph_2d.h
@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-#ifndef CARTOGRAPHER_MAPPING_2D_POSE_GRAPH_2D_H_
-#define CARTOGRAPHER_MAPPING_2D_POSE_GRAPH_2D_H_
+#ifndef CARTOGRAPHER_MAPPING_INTERNAL_2D_POSE_GRAPH_2D_H_
+#define CARTOGRAPHER_MAPPING_INTERNAL_2D_POSE_GRAPH_2D_H_
 
 #include <deque>
 #include <functional>
@@ -32,9 +32,9 @@
 #include "cartographer/common/mutex.h"
 #include "cartographer/common/thread_pool.h"
 #include "cartographer/common/time.h"
-#include "cartographer/mapping/2d/pose_graph/constraint_builder_2d.h"
-#include "cartographer/mapping/2d/pose_graph/optimization_problem_2d.h"
 #include "cartographer/mapping/2d/submap_2d.h"
+#include "cartographer/mapping/internal/2d/pose_graph/constraint_builder_2d.h"
+#include "cartographer/mapping/internal/2d/pose_graph/optimization_problem_2d.h"
 #include "cartographer/mapping/pose_graph.h"
 #include "cartographer/mapping/pose_graph_trimmer.h"
 #include "cartographer/mapping/trajectory_connectivity_state.h"
@@ -284,4 +284,4 @@ class PoseGraph2D : public PoseGraph {
 }  // namespace mapping
 }  // namespace cartographer
 
-#endif  // CARTOGRAPHER_MAPPING_2D_POSE_GRAPH_2D_H_
+#endif  // CARTOGRAPHER_MAPPING_INTERNAL_2D_POSE_GRAPH_2D_H_
diff --git a/cartographer/mapping/2d/pose_graph_2d_test.cc b/cartographer/mapping/internal/2d/pose_graph_2d_test.cc
similarity index 99%
rename from cartographer/mapping/2d/pose_graph_2d_test.cc
rename to cartographer/mapping/internal/2d/pose_graph_2d_test.cc
index 4fc217f..cdf5c33 100644
--- a/cartographer/mapping/2d/pose_graph_2d_test.cc
+++ b/cartographer/mapping/internal/2d/pose_graph_2d_test.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping/2d/pose_graph_2d.h"
+#include "cartographer/mapping/internal/2d/pose_graph_2d.h"
 
 #include <cmath>
 #include <memory>
diff --git a/cartographer/mapping/2d/ray_casting.cc b/cartographer/mapping/internal/2d/ray_casting.cc
similarity index 99%
rename from cartographer/mapping/2d/ray_casting.cc
rename to cartographer/mapping/internal/2d/ray_casting.cc
index 6691e5d..33d8d81 100644
--- a/cartographer/mapping/2d/ray_casting.cc
+++ b/cartographer/mapping/internal/2d/ray_casting.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping/2d/ray_casting.h"
+#include "cartographer/mapping/internal/2d/ray_casting.h"
 
 namespace cartographer {
 namespace mapping {
diff --git a/cartographer/mapping/2d/ray_casting.h b/cartographer/mapping/internal/2d/ray_casting.h
similarity index 88%
rename from cartographer/mapping/2d/ray_casting.h
rename to cartographer/mapping/internal/2d/ray_casting.h
index dee0c57..ae89a0b 100644
--- a/cartographer/mapping/2d/ray_casting.h
+++ b/cartographer/mapping/internal/2d/ray_casting.h
@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-#ifndef CARTOGRAPHER_MAPPING_2D_RAY_CASTING_H_
-#define CARTOGRAPHER_MAPPING_2D_RAY_CASTING_H_
+#ifndef CARTOGRAPHER_MAPPING_INTERNAL_2D_RAY_CASTING_H_
+#define CARTOGRAPHER_MAPPING_INTERNAL_2D_RAY_CASTING_H_
 
 #include <vector>
 
@@ -38,4 +38,4 @@ void CastRays(const sensor::RangeData& range_data,
 }  // namespace mapping
 }  // namespace cartographer
 
-#endif  // CARTOGRAPHER_MAPPING_2D_RAY_CASTING_H_
+#endif  // CARTOGRAPHER_MAPPING_INTERNAL_2D_RAY_CASTING_H_
diff --git a/cartographer/mapping/3d/imu_integration.h b/cartographer/mapping/internal/3d/imu_integration.h
similarity index 94%
rename from cartographer/mapping/3d/imu_integration.h
rename to cartographer/mapping/internal/3d/imu_integration.h
index 65f316c..88ee221 100644
--- a/cartographer/mapping/3d/imu_integration.h
+++ b/cartographer/mapping/internal/3d/imu_integration.h
@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-#ifndef CARTOGRAPHER_MAPPING_3D_IMU_INTEGRATION_H_
-#define CARTOGRAPHER_MAPPING_3D_IMU_INTEGRATION_H_
+#ifndef CARTOGRAPHER_MAPPING_INTERNAL_3D_IMU_INTEGRATION_H_
+#define CARTOGRAPHER_MAPPING_INTERNAL_3D_IMU_INTEGRATION_H_
 
 #include <algorithm>
 #include <deque>
@@ -95,4 +95,4 @@ IntegrateImuResult<double> IntegrateImu(const RangeType& imu_data,
 }  // namespace mapping
 }  // namespace cartographer
 
-#endif  // CARTOGRAPHER_MAPPING_3D_IMU_INTEGRATION_H_
+#endif  // CARTOGRAPHER_MAPPING_INTERNAL_3D_IMU_INTEGRATION_H_
diff --git a/cartographer/mapping/3d/local_slam_result_3d.cc b/cartographer/mapping/internal/3d/local_slam_result_3d.cc
similarity index 90%
rename from cartographer/mapping/3d/local_slam_result_3d.cc
rename to cartographer/mapping/internal/3d/local_slam_result_3d.cc
index ef42ad6..ef6eece 100644
--- a/cartographer/mapping/3d/local_slam_result_3d.cc
+++ b/cartographer/mapping/internal/3d/local_slam_result_3d.cc
@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping/3d/local_slam_result_3d.h"
-#include "cartographer/mapping/3d/pose_graph_3d.h"
+#include "cartographer/mapping/internal/3d/local_slam_result_3d.h"
+#include "cartographer/mapping/internal/3d/pose_graph_3d.h"
 
 namespace cartographer {
 namespace mapping {
diff --git a/cartographer/mapping/3d/local_slam_result_3d.h b/cartographer/mapping/internal/3d/local_slam_result_3d.h
similarity index 89%
rename from cartographer/mapping/3d/local_slam_result_3d.h
rename to cartographer/mapping/internal/3d/local_slam_result_3d.h
index 9cf0b8a..24a55b7 100644
--- a/cartographer/mapping/3d/local_slam_result_3d.h
+++ b/cartographer/mapping/internal/3d/local_slam_result_3d.h
@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-#ifndef CARTOGRAPHER_MAPPING_3D_LOCAL_SLAM_RESULT_3D_H_
-#define CARTOGRAPHER_MAPPING_3D_LOCAL_SLAM_RESULT_3D_H_
+#ifndef CARTOGRAPHER_MAPPING_INTERNAL_3D_LOCAL_SLAM_RESULT_3D_H_
+#define CARTOGRAPHER_MAPPING_INTERNAL_3D_LOCAL_SLAM_RESULT_3D_H_
 
 #include "cartographer/mapping/3d/submap_3d.h"
 #include "cartographer/mapping/local_slam_result_data.h"
@@ -46,4 +46,4 @@ class LocalSlamResult3D : public LocalSlamResultData {
 }  // namespace mapping
 }  // namespace cartographer
 
-#endif  // CARTOGRAPHER_MAPPING_3D_LOCAL_SLAM_RESULT_3D_H_
+#endif  // CARTOGRAPHER_MAPPING_INTERNAL_3D_LOCAL_SLAM_RESULT_3D_H_
diff --git a/cartographer/mapping/internal/3d/local_trajectory_builder_3d_test.cc b/cartographer/mapping/internal/3d/local_trajectory_builder_3d_test.cc
index 13b11d4..0cc156a 100644
--- a/cartographer/mapping/internal/3d/local_trajectory_builder_3d_test.cc
+++ b/cartographer/mapping/internal/3d/local_trajectory_builder_3d_test.cc
@@ -23,7 +23,7 @@
 #include "cartographer/common/lua_parameter_dictionary_test_helpers.h"
 #include "cartographer/common/time.h"
 #include "cartographer/mapping/3d/hybrid_grid.h"
-#include "cartographer/mapping/3d/local_trajectory_builder_options_3d.h"
+#include "cartographer/mapping/internal/3d/local_trajectory_builder_options_3d.h"
 #include "cartographer/sensor/range_data.h"
 #include "cartographer/transform/rigid_transform.h"
 #include "cartographer/transform/rigid_transform_test_helpers.h"
diff --git a/cartographer/mapping/3d/local_trajectory_builder_options_3d.cc b/cartographer/mapping/internal/3d/local_trajectory_builder_options_3d.cc
similarity index 97%
rename from cartographer/mapping/3d/local_trajectory_builder_options_3d.cc
rename to cartographer/mapping/internal/3d/local_trajectory_builder_options_3d.cc
index e964df9..513aa22 100644
--- a/cartographer/mapping/3d/local_trajectory_builder_options_3d.cc
+++ b/cartographer/mapping/internal/3d/local_trajectory_builder_options_3d.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping/3d/local_trajectory_builder_options_3d.h"
+#include "cartographer/mapping/internal/3d/local_trajectory_builder_options_3d.h"
 
 #include "cartographer/mapping/3d/scan_matching/ceres_scan_matcher_3d.h"
 #include "cartographer/mapping/3d/submap_3d.h"
diff --git a/cartographer/mapping/3d/local_trajectory_builder_options_3d.h b/cartographer/mapping/internal/3d/local_trajectory_builder_options_3d.h
similarity index 80%
rename from cartographer/mapping/3d/local_trajectory_builder_options_3d.h
rename to cartographer/mapping/internal/3d/local_trajectory_builder_options_3d.h
index e7165c5..5a0241b 100644
--- a/cartographer/mapping/3d/local_trajectory_builder_options_3d.h
+++ b/cartographer/mapping/internal/3d/local_trajectory_builder_options_3d.h
@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-#ifndef CARTOGRAPHER_MAPPING_3D_LOCAL_TRAJECTORY_BUILDER_OPTIONS_3D_H_
-#define CARTOGRAPHER_MAPPING_3D_LOCAL_TRAJECTORY_BUILDER_OPTIONS_3D_H_
+#ifndef CARTOGRAPHER_MAPPING_INTERNAL_3D_LOCAL_TRAJECTORY_BUILDER_OPTIONS_3D_H_
+#define CARTOGRAPHER_MAPPING_INTERNAL_3D_LOCAL_TRAJECTORY_BUILDER_OPTIONS_3D_H_
 
 #include "cartographer/common/lua_parameter_dictionary.h"
 #include "cartographer/mapping/3d/proto/local_trajectory_builder_options_3d.pb.h"
@@ -29,4 +29,4 @@ proto::LocalTrajectoryBuilderOptions3D CreateLocalTrajectoryBuilderOptions3D(
 }  // namespace mapping
 }  // namespace cartographer
 
-#endif  // CARTOGRAPHER_MAPPING_3D_LOCAL_TRAJECTORY_BUILDER_OPTIONS_3D_H_
+#endif  // CARTOGRAPHER_MAPPING_INTERNAL_3D_LOCAL_TRAJECTORY_BUILDER_OPTIONS_3D_H_
diff --git a/cartographer/mapping/3d/pose_graph/constraint_builder_3d.cc b/cartographer/mapping/internal/3d/pose_graph/constraint_builder_3d.cc
similarity index 99%
rename from cartographer/mapping/3d/pose_graph/constraint_builder_3d.cc
rename to cartographer/mapping/internal/3d/pose_graph/constraint_builder_3d.cc
index c1bb459..925d54d 100644
--- a/cartographer/mapping/3d/pose_graph/constraint_builder_3d.cc
+++ b/cartographer/mapping/internal/3d/pose_graph/constraint_builder_3d.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping/3d/pose_graph/constraint_builder_3d.h"
+#include "cartographer/mapping/internal/3d/pose_graph/constraint_builder_3d.h"
 
 #include <cmath>
 #include <functional>
diff --git a/cartographer/mapping/3d/pose_graph/constraint_builder_3d.h b/cartographer/mapping/internal/3d/pose_graph/constraint_builder_3d.h
similarity index 97%
rename from cartographer/mapping/3d/pose_graph/constraint_builder_3d.h
rename to cartographer/mapping/internal/3d/pose_graph/constraint_builder_3d.h
index f90e575..69e054a 100644
--- a/cartographer/mapping/3d/pose_graph/constraint_builder_3d.h
+++ b/cartographer/mapping/internal/3d/pose_graph/constraint_builder_3d.h
@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-#ifndef CARTOGRAPHER_MAPPING_3D_POSE_GRAPH_CONSTRAINT_BUILDER_3D_H_
-#define CARTOGRAPHER_MAPPING_3D_POSE_GRAPH_CONSTRAINT_BUILDER_3D_H_
+#ifndef CARTOGRAPHER_MAPPING_INTERNAL_3D_POSE_GRAPH_CONSTRAINT_BUILDER_3D_H_
+#define CARTOGRAPHER_MAPPING_INTERNAL_3D_POSE_GRAPH_CONSTRAINT_BUILDER_3D_H_
 
 #include <array>
 #include <deque>
@@ -195,4 +195,4 @@ class ConstraintBuilder3D {
 }  // namespace mapping
 }  // namespace cartographer
 
-#endif  // CARTOGRAPHER_MAPPING_3D_POSE_GRAPH_CONSTRAINT_BUILDER_3D_H_
+#endif  // CARTOGRAPHER_MAPPING_INTERNAL_3D_POSE_GRAPH_CONSTRAINT_BUILDER_3D_H_
diff --git a/cartographer/mapping/3d/pose_graph/landmark_cost_function_3d.h b/cartographer/mapping/internal/3d/pose_graph/landmark_cost_function_3d.h
similarity index 92%
rename from cartographer/mapping/3d/pose_graph/landmark_cost_function_3d.h
rename to cartographer/mapping/internal/3d/pose_graph/landmark_cost_function_3d.h
index 520b75d..393be39 100644
--- a/cartographer/mapping/3d/pose_graph/landmark_cost_function_3d.h
+++ b/cartographer/mapping/internal/3d/pose_graph/landmark_cost_function_3d.h
@@ -14,12 +14,12 @@
  * limitations under the License.
  */
 
-#ifndef CARTOGRAPHER_MAPPING_3D_POSE_GRAPH_LANDMARK_COST_FUNCTION_3D_H_
-#define CARTOGRAPHER_MAPPING_3D_POSE_GRAPH_LANDMARK_COST_FUNCTION_3D_H_
+#ifndef CARTOGRAPHER_MAPPING_INTERNAL_3D_POSE_GRAPH_LANDMARK_COST_FUNCTION_3D_H_
+#define CARTOGRAPHER_MAPPING_INTERNAL_3D_POSE_GRAPH_LANDMARK_COST_FUNCTION_3D_H_
 
 #include "Eigen/Core"
 #include "Eigen/Geometry"
-#include "cartographer/mapping/3d/pose_graph/optimization_problem_3d.h"
+#include "cartographer/mapping/internal/3d/pose_graph/optimization_problem_3d.h"
 #include "cartographer/mapping/pose_graph/cost_helpers.h"
 #include "cartographer/mapping/pose_graph_interface.h"
 #include "cartographer/transform/rigid_transform.h"
@@ -105,4 +105,4 @@ class LandmarkCostFunction3D {
 }  // namespace mapping
 }  // namespace cartographer
 
-#endif  // CARTOGRAPHER_MAPPING_3D_POSE_GRAPH_LANDMARK_COST_FUNCTION_3D_H_
+#endif  // CARTOGRAPHER_MAPPING_INTERNAL_3D_POSE_GRAPH_LANDMARK_COST_FUNCTION_3D_H_
diff --git a/cartographer/mapping/3d/pose_graph/landmark_cost_function_3d_test.cc b/cartographer/mapping/internal/3d/pose_graph/landmark_cost_function_3d_test.cc
similarity index 97%
rename from cartographer/mapping/3d/pose_graph/landmark_cost_function_3d_test.cc
rename to cartographer/mapping/internal/3d/pose_graph/landmark_cost_function_3d_test.cc
index 543395b..7ec671e 100644
--- a/cartographer/mapping/3d/pose_graph/landmark_cost_function_3d_test.cc
+++ b/cartographer/mapping/internal/3d/pose_graph/landmark_cost_function_3d_test.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping/3d/pose_graph/landmark_cost_function_3d.h"
+#include "cartographer/mapping/internal/3d/pose_graph/landmark_cost_function_3d.h"
 
 #include <memory>
 
diff --git a/cartographer/mapping/3d/pose_graph/optimization_problem_3d.cc b/cartographer/mapping/internal/3d/pose_graph/optimization_problem_3d.cc
similarity index 98%
rename from cartographer/mapping/3d/pose_graph/optimization_problem_3d.cc
rename to cartographer/mapping/internal/3d/pose_graph/optimization_problem_3d.cc
index 4ee9c15..8ba741b 100644
--- a/cartographer/mapping/3d/pose_graph/optimization_problem_3d.cc
+++ b/cartographer/mapping/internal/3d/pose_graph/optimization_problem_3d.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping/3d/pose_graph/optimization_problem_3d.h"
+#include "cartographer/mapping/internal/3d/pose_graph/optimization_problem_3d.h"
 
 #include <algorithm>
 #include <array>
@@ -30,12 +30,12 @@
 #include "cartographer/common/make_unique.h"
 #include "cartographer/common/math.h"
 #include "cartographer/common/time.h"
-#include "cartographer/mapping/3d/imu_integration.h"
-#include "cartographer/mapping/3d/pose_graph/landmark_cost_function_3d.h"
-#include "cartographer/mapping/3d/pose_graph/spa_cost_function_3d.h"
-#include "cartographer/mapping/3d/rotation_parameterization.h"
 #include "cartographer/mapping/internal/3d/acceleration_cost_function_3d.h"
+#include "cartographer/mapping/internal/3d/imu_integration.h"
+#include "cartographer/mapping/internal/3d/pose_graph/landmark_cost_function_3d.h"
+#include "cartographer/mapping/internal/3d/pose_graph/spa_cost_function_3d.h"
 #include "cartographer/mapping/internal/3d/rotation_cost_function_3d.h"
+#include "cartographer/mapping/internal/3d/rotation_parameterization.h"
 #include "cartographer/mapping/pose_graph/ceres_pose.h"
 #include "cartographer/transform/timestamped_transform.h"
 #include "cartographer/transform/transform.h"
diff --git a/cartographer/mapping/3d/pose_graph/optimization_problem_3d.h b/cartographer/mapping/internal/3d/pose_graph/optimization_problem_3d.h
similarity index 95%
rename from cartographer/mapping/3d/pose_graph/optimization_problem_3d.h
rename to cartographer/mapping/internal/3d/pose_graph/optimization_problem_3d.h
index 8eb9eb5..e3c487a 100644
--- a/cartographer/mapping/3d/pose_graph/optimization_problem_3d.h
+++ b/cartographer/mapping/internal/3d/pose_graph/optimization_problem_3d.h
@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-#ifndef CARTOGRAPHER_MAPPING_3D_POSE_GRAPH_OPTIMIZATION_PROBLEM_3D_H_
-#define CARTOGRAPHER_MAPPING_3D_POSE_GRAPH_OPTIMIZATION_PROBLEM_3D_H_
+#ifndef CARTOGRAPHER_MAPPING_INTERNAL_3D_POSE_GRAPH_OPTIMIZATION_PROBLEM_3D_H_
+#define CARTOGRAPHER_MAPPING_INTERNAL_3D_POSE_GRAPH_OPTIMIZATION_PROBLEM_3D_H_
 
 #include <array>
 #include <map>
@@ -125,4 +125,4 @@ class OptimizationProblem3D {
 }  // namespace mapping
 }  // namespace cartographer
 
-#endif  // CARTOGRAPHER_MAPPING_3D_POSE_GRAPH_OPTIMIZATION_PROBLEM_3D_H_
+#endif  // CARTOGRAPHER_MAPPING_INTERNAL_3D_POSE_GRAPH_OPTIMIZATION_PROBLEM_3D_H_
diff --git a/cartographer/mapping/3d/pose_graph/optimization_problem_3d_test.cc b/cartographer/mapping/internal/3d/pose_graph/optimization_problem_3d_test.cc
similarity index 98%
rename from cartographer/mapping/3d/pose_graph/optimization_problem_3d_test.cc
rename to cartographer/mapping/internal/3d/pose_graph/optimization_problem_3d_test.cc
index be329e9..d561cb1 100644
--- a/cartographer/mapping/3d/pose_graph/optimization_problem_3d_test.cc
+++ b/cartographer/mapping/internal/3d/pose_graph/optimization_problem_3d_test.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping/3d/pose_graph/optimization_problem_3d.h"
+#include "cartographer/mapping/internal/3d/pose_graph/optimization_problem_3d.h"
 
 #include <random>
 
diff --git a/cartographer/mapping/3d/pose_graph/spa_cost_function_3d.h b/cartographer/mapping/internal/3d/pose_graph/spa_cost_function_3d.h
similarity index 90%
rename from cartographer/mapping/3d/pose_graph/spa_cost_function_3d.h
rename to cartographer/mapping/internal/3d/pose_graph/spa_cost_function_3d.h
index 72d8b14..6654c13 100644
--- a/cartographer/mapping/3d/pose_graph/spa_cost_function_3d.h
+++ b/cartographer/mapping/internal/3d/pose_graph/spa_cost_function_3d.h
@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-#ifndef CARTOGRAPHER_MAPPING_3D_POSE_GRAPH_SPA_COST_FUNCTION_3D_H_
-#define CARTOGRAPHER_MAPPING_3D_POSE_GRAPH_SPA_COST_FUNCTION_3D_H_
+#ifndef CARTOGRAPHER_MAPPING_INTERNAL_3D_POSE_GRAPH_SPA_COST_FUNCTION_3D_H_
+#define CARTOGRAPHER_MAPPING_INTERNAL_3D_POSE_GRAPH_SPA_COST_FUNCTION_3D_H_
 
 #include <array>
 
@@ -66,4 +66,4 @@ class SpaCostFunction3D {
 }  // namespace mapping
 }  // namespace cartographer
 
-#endif  // CARTOGRAPHER_MAPPING_3D_POSE_GRAPH_SPA_COST_FUNCTION_3D_H_
+#endif  // CARTOGRAPHER_MAPPING_INTERNAL_3D_POSE_GRAPH_SPA_COST_FUNCTION_3D_H_
diff --git a/cartographer/mapping/3d/pose_graph_3d.cc b/cartographer/mapping/internal/3d/pose_graph_3d.cc
similarity index 99%
rename from cartographer/mapping/3d/pose_graph_3d.cc
rename to cartographer/mapping/internal/3d/pose_graph_3d.cc
index 55ecb3e..3b31aab 100644
--- a/cartographer/mapping/3d/pose_graph_3d.cc
+++ b/cartographer/mapping/internal/3d/pose_graph_3d.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping/3d/pose_graph_3d.h"
+#include "cartographer/mapping/internal/3d/pose_graph_3d.h"
 
 #include <algorithm>
 #include <cmath>
diff --git a/cartographer/mapping/3d/pose_graph_3d.h b/cartographer/mapping/internal/3d/pose_graph_3d.h
similarity index 97%
rename from cartographer/mapping/3d/pose_graph_3d.h
rename to cartographer/mapping/internal/3d/pose_graph_3d.h
index 9e0cc93..4d5cde4 100644
--- a/cartographer/mapping/3d/pose_graph_3d.h
+++ b/cartographer/mapping/internal/3d/pose_graph_3d.h
@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-#ifndef CARTOGRAPHER_MAPPING_3D_POSE_GRAPH_3D_H_
-#define CARTOGRAPHER_MAPPING_3D_POSE_GRAPH_3D_H_
+#ifndef CARTOGRAPHER_MAPPING_INTERNAL_3D_POSE_GRAPH_3D_H_
+#define CARTOGRAPHER_MAPPING_INTERNAL_3D_POSE_GRAPH_3D_H_
 
 #include <deque>
 #include <functional>
@@ -32,9 +32,9 @@
 #include "cartographer/common/mutex.h"
 #include "cartographer/common/thread_pool.h"
 #include "cartographer/common/time.h"
-#include "cartographer/mapping/3d/pose_graph/constraint_builder_3d.h"
-#include "cartographer/mapping/3d/pose_graph/optimization_problem_3d.h"
 #include "cartographer/mapping/3d/submap_3d.h"
+#include "cartographer/mapping/internal/3d/pose_graph/constraint_builder_3d.h"
+#include "cartographer/mapping/internal/3d/pose_graph/optimization_problem_3d.h"
 #include "cartographer/mapping/pose_graph.h"
 #include "cartographer/mapping/pose_graph_trimmer.h"
 #include "cartographer/mapping/trajectory_connectivity_state.h"
@@ -288,4 +288,4 @@ class PoseGraph3D : public PoseGraph {
 }  // namespace mapping
 }  // namespace cartographer
 
-#endif  // CARTOGRAPHER_MAPPING_3D_POSE_GRAPH_3D_H_
+#endif  // CARTOGRAPHER_MAPPING_INTERNAL_3D_POSE_GRAPH_3D_H_
diff --git a/cartographer/mapping/3d/rotation_parameterization.h b/cartographer/mapping/internal/3d/rotation_parameterization.h
similarity index 91%
rename from cartographer/mapping/3d/rotation_parameterization.h
rename to cartographer/mapping/internal/3d/rotation_parameterization.h
index c554287..4ce0055 100644
--- a/cartographer/mapping/3d/rotation_parameterization.h
+++ b/cartographer/mapping/internal/3d/rotation_parameterization.h
@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-#ifndef CARTOGRAPHER_MAPPING_3D_ROTATION_PARAMETERIZATION_H_
-#define CARTOGRAPHER_MAPPING_3D_ROTATION_PARAMETERIZATION_H_
+#ifndef CARTOGRAPHER_MAPPING_INTERNAL_3D_ROTATION_PARAMETERIZATION_H_
+#define CARTOGRAPHER_MAPPING_INTERNAL_3D_ROTATION_PARAMETERIZATION_H_
 
 #include "cartographer/common/math.h"
 #include "ceres/jet.h"
@@ -64,4 +64,4 @@ struct ConstantYawQuaternionPlus {
 }  // namespace mapping
 }  // namespace cartographer
 
-#endif  // CARTOGRAPHER_MAPPING_3D_ROTATION_PARAMETERIZATION_H_
+#endif  // CARTOGRAPHER_MAPPING_INTERNAL_3D_ROTATION_PARAMETERIZATION_H_
diff --git a/cartographer/mapping/internal/global_trajectory_builder.h b/cartographer/mapping/internal/global_trajectory_builder.h
index db036b6..a6fe399 100644
--- a/cartographer/mapping/internal/global_trajectory_builder.h
+++ b/cartographer/mapping/internal/global_trajectory_builder.h
@@ -19,10 +19,10 @@
 
 #include <memory>
 
-#include "cartographer/mapping/2d/pose_graph_2d.h"
-#include "cartographer/mapping/3d/pose_graph_3d.h"
 #include "cartographer/mapping/internal/2d/local_trajectory_builder_2d.h"
+#include "cartographer/mapping/internal/2d/pose_graph_2d.h"
 #include "cartographer/mapping/internal/3d/local_trajectory_builder_3d.h"
+#include "cartographer/mapping/internal/3d/pose_graph_3d.h"
 #include "cartographer/mapping/local_slam_result_data.h"
 #include "cartographer/mapping/trajectory_builder_interface.h"
 
diff --git a/cartographer/mapping/map_builder.cc b/cartographer/mapping/map_builder.cc
index 3ceff97..38fa47b 100644
--- a/cartographer/mapping/map_builder.cc
+++ b/cartographer/mapping/map_builder.cc
@@ -24,11 +24,11 @@
 
 #include "cartographer/common/make_unique.h"
 #include "cartographer/common/time.h"
-#include "cartographer/mapping/2d/pose_graph_2d.h"
-#include "cartographer/mapping/3d/pose_graph_3d.h"
 #include "cartographer/mapping/collated_trajectory_builder.h"
 #include "cartographer/mapping/internal/2d/local_trajectory_builder_2d.h"
+#include "cartographer/mapping/internal/2d/pose_graph_2d.h"
 #include "cartographer/mapping/internal/3d/local_trajectory_builder_3d.h"
+#include "cartographer/mapping/internal/3d/pose_graph_3d.h"
 #include "cartographer/mapping/internal/global_trajectory_builder.h"
 #include "cartographer/sensor/collator.h"
 #include "cartographer/sensor/range_data.h"
diff --git a/cartographer/mapping/trajectory_builder_interface.cc b/cartographer/mapping/trajectory_builder_interface.cc
index ff5ce79..36057bb 100644
--- a/cartographer/mapping/trajectory_builder_interface.cc
+++ b/cartographer/mapping/trajectory_builder_interface.cc
@@ -16,8 +16,8 @@
 
 #include "cartographer/mapping/trajectory_builder_interface.h"
 
-#include "cartographer/mapping/2d/local_trajectory_builder_options_2d.h"
-#include "cartographer/mapping/3d/local_trajectory_builder_options_3d.h"
+#include "cartographer/mapping/internal/2d/local_trajectory_builder_options_2d.h"
+#include "cartographer/mapping/internal/3d/local_trajectory_builder_options_3d.h"
 #include "cartographer/mapping/local_slam_result_data.h"
 
 namespace cartographer {
diff --git a/cartographer/metrics/register.cc b/cartographer/metrics/register.cc
index c2e49a8..4576693 100644
--- a/cartographer/metrics/register.cc
+++ b/cartographer/metrics/register.cc
@@ -16,10 +16,10 @@
 
 #include "cartographer/metrics/register.h"
 
-#include "cartographer/mapping/2d/pose_graph/constraint_builder_2d.h"
-#include "cartographer/mapping/3d/pose_graph/constraint_builder_3d.h"
 #include "cartographer/mapping/internal/2d/local_trajectory_builder_2d.h"
+#include "cartographer/mapping/internal/2d/pose_graph/constraint_builder_2d.h"
 #include "cartographer/mapping/internal/3d/local_trajectory_builder_3d.h"
+#include "cartographer/mapping/internal/3d/pose_graph/constraint_builder_3d.h"
 
 namespace cartographer {
 namespace metrics {