diff --git a/cartographer/mapping_3d/submaps.cc b/cartographer/mapping_3d/submaps.cc
index 7a4f94d..8b1842b 100644
--- a/cartographer/mapping_3d/submaps.cc
+++ b/cartographer/mapping_3d/submaps.cc
@@ -178,6 +178,20 @@ void InsertSegmentsIntoProbabilityGrid(
   }
 }
 
+// Filters 'laser_fan', retaining only the returns that have no more than
+// 'max_range' distance from the laser origin. Removes misses and reflectivity
+// information.
+sensor::LaserFan FilterLaserFanByMaxRange(const sensor::LaserFan& laser_fan,
+                                          const float max_range) {
+  sensor::LaserFan result{laser_fan.origin, {}, {}, {}};
+  for (const Eigen::Vector3f& return_ : laser_fan.returns) {
+    if ((return_ - laser_fan.origin).norm() <= max_range) {
+      result.returns.push_back(return_);
+    }
+  }
+  return result;
+}
+
 }  // namespace
 
 void InsertIntoProbabilityGrid(
@@ -273,8 +287,8 @@ void Submaps::InsertLaserFan(const sensor::LaserFan& laser_fan) {
   for (const int index : insertion_indices()) {
     Submap* submap = submaps_[index].get();
     laser_fan_inserter_.Insert(
-        sensor::FilterLaserFanByMaxRange(laser_fan,
-                                         options_.high_resolution_max_range()),
+        FilterLaserFanByMaxRange(laser_fan,
+                                 options_.high_resolution_max_range()),
         &submap->high_resolution_hybrid_grid);
     laser_fan_inserter_.Insert(laser_fan, &submap->low_resolution_hybrid_grid);
     submap->end_laser_fan_index = num_laser_fans_;
diff --git a/cartographer/sensor/laser.cc b/cartographer/sensor/laser.cc
index 46a81e6..36bbb10 100644
--- a/cartographer/sensor/laser.cc
+++ b/cartographer/sensor/laser.cc
@@ -94,17 +94,6 @@ LaserFan TransformLaserFan(const LaserFan& laser_fan,
   };
 }
 
-LaserFan FilterLaserFanByMaxRange(const LaserFan& laser_fan,
-                                  const float max_range) {
-  LaserFan result{laser_fan.origin, {}, {}, {}};
-  for (const Eigen::Vector3f& return_ : laser_fan.returns) {
-    if ((return_ - laser_fan.origin).norm() <= max_range) {
-      result.returns.push_back(return_);
-    }
-  }
-  return result;
-}
-
 LaserFan CropLaserFan(const LaserFan& laser_fan, const float min_z,
                       const float max_z) {
   return LaserFan{laser_fan.origin, Crop(laser_fan.returns, min_z, max_z),
diff --git a/cartographer/sensor/laser.h b/cartographer/sensor/laser.h
index 0d511f3..0a023be 100644
--- a/cartographer/sensor/laser.h
+++ b/cartographer/sensor/laser.h
@@ -54,11 +54,6 @@ LaserFan FromProto(const proto::LaserFan& proto);
 LaserFan TransformLaserFan(const LaserFan& laser_fan,
                            const transform::Rigid3f& transform);
 
-// Filter a 'laser_fan', retaining only the returns that have no more than
-// 'max_range' distance from the laser origin. Removes misses and reflectivity
-// information.
-LaserFan FilterLaserFanByMaxRange(const LaserFan& laser_fan, float max_range);
-
 // Crops 'laser_fan' according to the region defined by 'min_z' and 'max_z'.
 LaserFan CropLaserFan(const LaserFan& laser_fan, float min_z, float max_z);