diff --git a/cartographer/mapping/2d/submap_2d.cc b/cartographer/mapping/2d/submap_2d.cc
index feb30fc..a84d48e 100644
--- a/cartographer/mapping/2d/submap_2d.cc
+++ b/cartographer/mapping/2d/submap_2d.cc
@@ -26,7 +26,7 @@
 #include "absl/memory/memory.h"
 #include "cartographer/common/port.h"
 #include "cartographer/mapping/2d/probability_grid_range_data_inserter_2d.h"
-#include "cartographer/mapping/2d/tsdf_range_data_inserter_2d.h"
+#include "cartographer/mapping/internal/2d/tsdf_range_data_inserter_2d.h"
 #include "cartographer/mapping/range_data_inserter_interface.h"
 #include "glog/logging.h"
 
diff --git a/cartographer/mapping/imu_tracker.cc b/cartographer/mapping/imu_tracker.cc
index 45391d0..8aed29c 100644
--- a/cartographer/mapping/imu_tracker.cc
+++ b/cartographer/mapping/imu_tracker.cc
@@ -20,7 +20,7 @@
 #include <limits>
 
 #include "cartographer/common/math.h"
-#include "cartographer/mapping/eigen_quaterniond_from_two_vectors.h"
+#include "cartographer/mapping/internal/eigen_quaterniond_from_two_vectors.h"
 #include "cartographer/transform/transform.h"
 #include "glog/logging.h"
 
diff --git a/cartographer/mapping/imu_tracker_test.cc b/cartographer/mapping/imu_tracker_test.cc
index 88ae846..10992ed 100644
--- a/cartographer/mapping/imu_tracker_test.cc
+++ b/cartographer/mapping/imu_tracker_test.cc
@@ -17,7 +17,7 @@
 #include "cartographer/mapping/imu_tracker.h"
 
 #include "absl/memory/memory.h"
-#include "cartographer/mapping/eigen_quaterniond_from_two_vectors.h"
+#include "cartographer/mapping/internal/eigen_quaterniond_from_two_vectors.h"
 #include "gtest/gtest.h"
 
 namespace cartographer {
diff --git a/cartographer/mapping/internal/2d/scan_matching/real_time_correlative_scan_matcher_2d_test.cc b/cartographer/mapping/internal/2d/scan_matching/real_time_correlative_scan_matcher_2d_test.cc
index f8eef22..27df5a7 100644
--- a/cartographer/mapping/internal/2d/scan_matching/real_time_correlative_scan_matcher_2d_test.cc
+++ b/cartographer/mapping/internal/2d/scan_matching/real_time_correlative_scan_matcher_2d_test.cc
@@ -25,7 +25,7 @@
 #include "cartographer/mapping/2d/probability_grid.h"
 #include "cartographer/mapping/2d/probability_grid_range_data_inserter_2d.h"
 #include "cartographer/mapping/2d/tsdf_2d.h"
-#include "cartographer/mapping/2d/tsdf_range_data_inserter_2d.h"
+#include "cartographer/mapping/internal/2d/tsdf_range_data_inserter_2d.h"
 #include "cartographer/mapping/internal/scan_matching/real_time_correlative_scan_matcher.h"
 #include "cartographer/sensor/point_cloud.h"
 #include "cartographer/transform/transform.h"
diff --git a/cartographer/mapping/internal/2d/scan_matching/tsdf_match_cost_function_2d_test.cc b/cartographer/mapping/internal/2d/scan_matching/tsdf_match_cost_function_2d_test.cc
index 3311ace..04c6f05 100644
--- a/cartographer/mapping/internal/2d/scan_matching/tsdf_match_cost_function_2d_test.cc
+++ b/cartographer/mapping/internal/2d/scan_matching/tsdf_match_cost_function_2d_test.cc
@@ -19,7 +19,7 @@
 #include "cartographer/common/lua_parameter_dictionary.h"
 #include "cartographer/common/lua_parameter_dictionary_test_helpers.h"
 #include "cartographer/mapping/2d/tsdf_2d.h"
-#include "cartographer/mapping/2d/tsdf_range_data_inserter_2d.h"
+#include "cartographer/mapping/internal/2d/tsdf_range_data_inserter_2d.h"
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
 
diff --git a/cartographer/mapping/2d/tsdf_range_data_inserter_2d.cc b/cartographer/mapping/internal/2d/tsdf_range_data_inserter_2d.cc
similarity index 99%
rename from cartographer/mapping/2d/tsdf_range_data_inserter_2d.cc
rename to cartographer/mapping/internal/2d/tsdf_range_data_inserter_2d.cc
index 7a6a4e7..7e6bd3f 100644
--- a/cartographer/mapping/2d/tsdf_range_data_inserter_2d.cc
+++ b/cartographer/mapping/internal/2d/tsdf_range_data_inserter_2d.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping/2d/tsdf_range_data_inserter_2d.h"
+#include "cartographer/mapping/internal/2d/tsdf_range_data_inserter_2d.h"
 
 #include "cartographer/mapping/internal/2d/normal_estimation_2d.h"
 #include "cartographer/mapping/internal/2d/ray_to_pixel_mask.h"
diff --git a/cartographer/mapping/2d/tsdf_range_data_inserter_2d.h b/cartographer/mapping/internal/2d/tsdf_range_data_inserter_2d.h
similarity index 100%
rename from cartographer/mapping/2d/tsdf_range_data_inserter_2d.h
rename to cartographer/mapping/internal/2d/tsdf_range_data_inserter_2d.h
diff --git a/cartographer/mapping/2d/tsdf_range_data_inserter_2d_test.cc b/cartographer/mapping/internal/2d/tsdf_range_data_inserter_2d_test.cc
similarity index 99%
rename from cartographer/mapping/2d/tsdf_range_data_inserter_2d_test.cc
rename to cartographer/mapping/internal/2d/tsdf_range_data_inserter_2d_test.cc
index 7e59508..da06a89 100644
--- a/cartographer/mapping/2d/tsdf_range_data_inserter_2d_test.cc
+++ b/cartographer/mapping/internal/2d/tsdf_range_data_inserter_2d_test.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping/2d/tsdf_range_data_inserter_2d.h"
+#include "cartographer/mapping/internal/2d/tsdf_range_data_inserter_2d.h"
 
 #include "cartographer/common/lua_parameter_dictionary.h"
 #include "cartographer/common/lua_parameter_dictionary_test_helpers.h"
diff --git a/cartographer/mapping/eigen_quaterniond_from_two_vectors.cc b/cartographer/mapping/internal/eigen_quaterniond_from_two_vectors.cc
similarity index 91%
rename from cartographer/mapping/eigen_quaterniond_from_two_vectors.cc
rename to cartographer/mapping/internal/eigen_quaterniond_from_two_vectors.cc
index af0aac7..e0edcb7 100644
--- a/cartographer/mapping/eigen_quaterniond_from_two_vectors.cc
+++ b/cartographer/mapping/internal/eigen_quaterniond_from_two_vectors.cc
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping/eigen_quaterniond_from_two_vectors.h"
+#include "cartographer/mapping/internal/eigen_quaterniond_from_two_vectors.h"
 
 namespace cartographer {
 namespace mapping {
diff --git a/cartographer/mapping/eigen_quaterniond_from_two_vectors.h b/cartographer/mapping/internal/eigen_quaterniond_from_two_vectors.h
similarity index 100%
rename from cartographer/mapping/eigen_quaterniond_from_two_vectors.h
rename to cartographer/mapping/internal/eigen_quaterniond_from_two_vectors.h
diff --git a/cartographer/mapping/imu_based_pose_extrapolator.cc b/cartographer/mapping/internal/imu_based_pose_extrapolator.cc
similarity index 99%
rename from cartographer/mapping/imu_based_pose_extrapolator.cc
rename to cartographer/mapping/internal/imu_based_pose_extrapolator.cc
index 6c9d72f..ddb88ea 100644
--- a/cartographer/mapping/imu_based_pose_extrapolator.cc
+++ b/cartographer/mapping/internal/imu_based_pose_extrapolator.cc
@@ -14,14 +14,14 @@
  * limitations under the License.
  */
 
-#include "cartographer/mapping/imu_based_pose_extrapolator.h"
+#include "cartographer/mapping/internal/imu_based_pose_extrapolator.h"
 
 #include <algorithm>
 
 #include "absl/memory/memory.h"
-#include "cartographer/mapping/eigen_quaterniond_from_two_vectors.h"
 #include "cartographer/mapping/internal/3d/imu_integration.h"
 #include "cartographer/mapping/internal/3d/rotation_parameterization.h"
+#include "cartographer/mapping/internal/eigen_quaterniond_from_two_vectors.h"
 #include "cartographer/mapping/internal/optimization/ceres_pose.h"
 #include "cartographer/mapping/internal/optimization/cost_functions/acceleration_cost_function_3d.h"
 #include "cartographer/mapping/internal/optimization/cost_functions/rotation_cost_function_3d.h"
diff --git a/cartographer/mapping/imu_based_pose_extrapolator.h b/cartographer/mapping/internal/imu_based_pose_extrapolator.h
similarity index 100%
rename from cartographer/mapping/imu_based_pose_extrapolator.h
rename to cartographer/mapping/internal/imu_based_pose_extrapolator.h
diff --git a/cartographer/mapping/pose_extrapolator_interface.cc b/cartographer/mapping/pose_extrapolator_interface.cc
index 413a8da..b0b504f 100644
--- a/cartographer/mapping/pose_extrapolator_interface.cc
+++ b/cartographer/mapping/pose_extrapolator_interface.cc
@@ -18,7 +18,7 @@
 
 #include "cartographer/common/ceres_solver_options.h"
 #include "cartographer/common/time.h"
-#include "cartographer/mapping/imu_based_pose_extrapolator.h"
+#include "cartographer/mapping/internal/imu_based_pose_extrapolator.h"
 #include "cartographer/mapping/pose_extrapolator.h"
 
 namespace cartographer {
diff --git a/cartographer/mapping/pose_extrapolator_test.cc b/cartographer/mapping/pose_extrapolator_test.cc
index 38afc84..00ef86f 100644
--- a/cartographer/mapping/pose_extrapolator_test.cc
+++ b/cartographer/mapping/pose_extrapolator_test.cc
@@ -18,7 +18,7 @@
 
 #include "Eigen/Geometry"
 #include "absl/memory/memory.h"
-#include "cartographer/mapping/eigen_quaterniond_from_two_vectors.h"
+#include "cartographer/mapping/internal/eigen_quaterniond_from_two_vectors.h"
 #include "cartographer/transform/rigid_transform_test_helpers.h"
 #include "gtest/gtest.h"
 
diff --git a/cartographer/mapping/range_data_inserter_interface.cc b/cartographer/mapping/range_data_inserter_interface.cc
index 79d8c8d..571987c 100644
--- a/cartographer/mapping/range_data_inserter_interface.cc
+++ b/cartographer/mapping/range_data_inserter_interface.cc
@@ -17,7 +17,7 @@
 #include "cartographer/mapping/range_data_inserter_interface.h"
 
 #include "cartographer/mapping/2d/probability_grid_range_data_inserter_2d.h"
-#include "cartographer/mapping/2d/tsdf_range_data_inserter_2d.h"
+#include "cartographer/mapping/internal/2d/tsdf_range_data_inserter_2d.h"
 
 namespace cartographer {
 namespace mapping {
@@ -46,4 +46,4 @@ proto::RangeDataInserterOptions CreateRangeDataInserterOptions(
   return options;
 }
 }  // namespace mapping
-}  // namespace cartographer
\ No newline at end of file
+}  // namespace cartographer