diff --git a/cartographer/mapping/trajectory_connectivity.cc b/cartographer/mapping/trajectory_connectivity.cc
index 1ae65e3..e3def82 100644
--- a/cartographer/mapping/trajectory_connectivity.cc
+++ b/cartographer/mapping/trajectory_connectivity.cc
@@ -98,9 +98,8 @@ int TrajectoryConnectivity::ConnectionCount(const int trajectory_id_a,
 proto::TrajectoryConnectivity ToProto(
     std::vector<std::vector<int>> connected_components) {
   proto::TrajectoryConnectivity proto;
-  for (const auto& connected_component : connected_components) {
-    std::sort(connected_components.back().begin(),
-              connected_components.back().end());
+  for (auto& connected_component : connected_components) {
+    std::sort(connected_component.begin(), connected_component.end());
   }
   std::sort(connected_components.begin(), connected_components.end());
   for (const auto& connected_component : connected_components) {
diff --git a/cartographer/mapping_3d/sparse_pose_graph/constraint_builder.cc b/cartographer/mapping_3d/sparse_pose_graph/constraint_builder.cc
index 84cb65f..0d52c7a 100644
--- a/cartographer/mapping_3d/sparse_pose_graph/constraint_builder.cc
+++ b/cartographer/mapping_3d/sparse_pose_graph/constraint_builder.cc
@@ -30,7 +30,6 @@
 #include "cartographer/common/math.h"
 #include "cartographer/common/thread_pool.h"
 #include "cartographer/kalman_filter/pose_tracker.h"
-#include "cartographer/mapping/submaps.h"
 #include "cartographer/mapping_3d/scan_matching/proto/ceres_scan_matcher_options.pb.h"
 #include "cartographer/mapping_3d/scan_matching/proto/fast_correlative_scan_matcher_options.pb.h"
 #include "cartographer/transform/transform.h"