diff --git a/cartographer/mapping_3d/sparse_pose_graph/constraint_builder.cc b/cartographer/mapping_3d/sparse_pose_graph/constraint_builder.cc
index d526240..d007c0b 100644
--- a/cartographer/mapping_3d/sparse_pose_graph/constraint_builder.cc
+++ b/cartographer/mapping_3d/sparse_pose_graph/constraint_builder.cc
@@ -75,8 +75,7 @@ void ConstraintBuilder::MaybeAddConstraint(
     const int current_computation = current_computation_;
     ScheduleSubmapScanMatcherConstructionAndQueueWorkItem(
         submap_id, submap_nodes, submap, [=]() EXCLUDES(mutex_) {
-          ComputeConstraint(submap_id, submap, node_id,
-                            false,   /* match_full_submap */
+          ComputeConstraint(submap_id, node_id, false, /* match_full_submap */
                             nullptr, /* trajectory_connectivity */
                             compressed_point_cloud, initial_pose, constraint);
           FinishComputation(current_computation);
@@ -98,10 +97,10 @@ void ConstraintBuilder::MaybeAddGlobalConstraint(
   const int current_computation = current_computation_;
   ScheduleSubmapScanMatcherConstructionAndQueueWorkItem(
       submap_id, submap_nodes, submap, [=]() EXCLUDES(mutex_) {
-        ComputeConstraint(
-            submap_id, submap, node_id, true, /* match_full_submap */
-            trajectory_connectivity, compressed_point_cloud,
-            transform::Rigid3d::Rotation(gravity_alignment), constraint);
+        ComputeConstraint(submap_id, node_id, true, /* match_full_submap */
+                          trajectory_connectivity, compressed_point_cloud,
+                          transform::Rigid3d::Rotation(gravity_alignment),
+                          constraint);
         FinishComputation(current_computation);
       });
 }
@@ -169,8 +168,8 @@ ConstraintBuilder::GetSubmapScanMatcher(const mapping::SubmapId& submap_id) {
 }
 
 void ConstraintBuilder::ComputeConstraint(
-    const mapping::SubmapId& submap_id, const Submap* const submap,
-    const mapping::NodeId& node_id, bool match_full_submap,
+    const mapping::SubmapId& submap_id, const mapping::NodeId& node_id,
+    bool match_full_submap,
     mapping::TrajectoryConnectivity* trajectory_connectivity,
     const sensor::CompressedPointCloud* const compressed_point_cloud,
     const transform::Rigid3d& initial_pose,
diff --git a/cartographer/mapping_3d/sparse_pose_graph/constraint_builder.h b/cartographer/mapping_3d/sparse_pose_graph/constraint_builder.h
index 81dc868..590810b 100644
--- a/cartographer/mapping_3d/sparse_pose_graph/constraint_builder.h
+++ b/cartographer/mapping_3d/sparse_pose_graph/constraint_builder.h
@@ -135,14 +135,14 @@ class ConstraintBuilder {
       const mapping::SubmapId& submap_id) EXCLUDES(mutex_);
 
   // Runs in a background thread and does computations for an additional
-  // constraint, assuming 'submap' and 'point_cloud' do not change anymore.
+  // constraint.
   // If 'match_full_submap' is true, and global localization succeeds, will
   // connect 'node_id.trajectory_id' and 'submap_id.trajectory_id' in
   // 'trajectory_connectivity'.
   // As output, it may create a new Constraint in 'constraint'.
   void ComputeConstraint(
-      const mapping::SubmapId& submap_id, const Submap* submap,
-      const mapping::NodeId& node_id, bool match_full_submap,
+      const mapping::SubmapId& submap_id, const mapping::NodeId& node_id,
+      bool match_full_submap,
       mapping::TrajectoryConnectivity* trajectory_connectivity,
       const sensor::CompressedPointCloud* compressed_point_cloud,
       const transform::Rigid3d& initial_pose,