diff --git a/cartographer/mapping/map_builder.cc b/cartographer/mapping/map_builder.cc
index d36de3b..4ecb5e1 100644
--- a/cartographer/mapping/map_builder.cc
+++ b/cartographer/mapping/map_builder.cc
@@ -173,7 +173,8 @@ void MapBuilder::SerializeState(io::ProtoStreamWriter* const writer) {
           submap_id_data.id.trajectory_id);
       submap_proto->mutable_submap_id()->set_submap_index(
           submap_id_data.id.submap_index);
-      submap_id_data.data.submap->ToProto(submap_proto);
+      submap_id_data.data.submap->ToProto(
+          submap_proto, true /* include_probability_grid_data */);
       writer->WriteProto(proto);
     }
   }
diff --git a/cartographer/mapping/submaps.h b/cartographer/mapping/submaps.h
index 6ff37f1..840ad50 100644
--- a/cartographer/mapping/submaps.h
+++ b/cartographer/mapping/submaps.h
@@ -63,7 +63,8 @@ class Submap {
       : local_pose_(local_submap_pose) {}
   virtual ~Submap() {}
 
-  virtual void ToProto(proto::Submap* proto) const = 0;
+  virtual void ToProto(proto::Submap* proto,
+                       bool include_probability_grid_data) const = 0;
   virtual void UpdateFromProto(const proto::Submap& proto) = 0;
 
   // Pose of this submap in the local map frame.
diff --git a/cartographer/mapping_2d/submaps.cc b/cartographer/mapping_2d/submaps.cc
index 9eac079..aef515a 100644
--- a/cartographer/mapping_2d/submaps.cc
+++ b/cartographer/mapping_2d/submaps.cc
@@ -74,12 +74,15 @@ Submap::Submap(const mapping::proto::Submap2D& proto)
   finished_ = proto.finished();
 }
 
-void Submap::ToProto(mapping::proto::Submap* const proto) const {
+void Submap::ToProto(mapping::proto::Submap* const proto,
+                     bool include_probability_grid_data) const {
   auto* const submap_2d = proto->mutable_submap_2d();
   *submap_2d->mutable_local_pose() = transform::ToProto(local_pose());
   submap_2d->set_num_range_data(num_range_data());
   submap_2d->set_finished(finished_);
-  *submap_2d->mutable_probability_grid() = probability_grid_.ToProto();
+  if (include_probability_grid_data) {
+    *submap_2d->mutable_probability_grid() = probability_grid_.ToProto();
+  }
 }
 
 void Submap::UpdateFromProto(const mapping::proto::Submap& proto) {
diff --git a/cartographer/mapping_2d/submaps.h b/cartographer/mapping_2d/submaps.h
index 67c8109..04ed518 100644
--- a/cartographer/mapping_2d/submaps.h
+++ b/cartographer/mapping_2d/submaps.h
@@ -47,7 +47,8 @@ class Submap : public mapping::Submap {
   Submap(const MapLimits& limits, const Eigen::Vector2f& origin);
   explicit Submap(const mapping::proto::Submap2D& proto);
 
-  void ToProto(mapping::proto::Submap* proto) const override;
+  void ToProto(mapping::proto::Submap* proto,
+               bool include_probability_grid_data) const override;
   void UpdateFromProto(const mapping::proto::Submap& proto) override;
 
   const ProbabilityGrid& probability_grid() const { return probability_grid_; }
diff --git a/cartographer/mapping_2d/submaps_test.cc b/cartographer/mapping_2d/submaps_test.cc
index a89d049..9981489 100644
--- a/cartographer/mapping_2d/submaps_test.cc
+++ b/cartographer/mapping_2d/submaps_test.cc
@@ -72,7 +72,7 @@ TEST(SubmapsTest, ToFromProto) {
   Submap expected(MapLimits(1., Eigen::Vector2d(2., 3.), CellLimits(100, 110)),
                   Eigen::Vector2f(4.f, 5.f));
   mapping::proto::Submap proto;
-  expected.ToProto(&proto);
+  expected.ToProto(&proto, true /* include_probability_grid_data */);
   EXPECT_TRUE(proto.has_submap_2d());
   EXPECT_FALSE(proto.has_submap_3d());
   const auto actual = Submap(proto.submap_2d());
diff --git a/cartographer/mapping_3d/submaps.cc b/cartographer/mapping_3d/submaps.cc
index be4e426..5a425d0 100644
--- a/cartographer/mapping_3d/submaps.cc
+++ b/cartographer/mapping_3d/submaps.cc
@@ -215,15 +215,18 @@ Submap::Submap(const mapping::proto::Submap3D& proto)
   finished_ = proto.finished();
 }
 
-void Submap::ToProto(mapping::proto::Submap* const proto) const {
+void Submap::ToProto(mapping::proto::Submap* const proto,
+                     bool include_probability_grid_data) const {
   auto* const submap_3d = proto->mutable_submap_3d();
   *submap_3d->mutable_local_pose() = transform::ToProto(local_pose());
   submap_3d->set_num_range_data(num_range_data());
   submap_3d->set_finished(finished_);
-  *submap_3d->mutable_high_resolution_hybrid_grid() =
-      high_resolution_hybrid_grid().ToProto();
-  *submap_3d->mutable_low_resolution_hybrid_grid() =
-      low_resolution_hybrid_grid().ToProto();
+  if (include_probability_grid_data) {
+    *submap_3d->mutable_high_resolution_hybrid_grid() =
+        high_resolution_hybrid_grid().ToProto();
+    *submap_3d->mutable_low_resolution_hybrid_grid() =
+        low_resolution_hybrid_grid().ToProto();
+  }
 }
 
 void Submap::UpdateFromProto(const mapping::proto::Submap& proto) {
diff --git a/cartographer/mapping_3d/submaps.h b/cartographer/mapping_3d/submaps.h
index cd16e60..d6635ee 100644
--- a/cartographer/mapping_3d/submaps.h
+++ b/cartographer/mapping_3d/submaps.h
@@ -47,7 +47,8 @@ class Submap : public mapping::Submap {
          const transform::Rigid3d& local_submap_pose);
   explicit Submap(const mapping::proto::Submap3D& proto);
 
-  void ToProto(mapping::proto::Submap* proto) const override;
+  void ToProto(mapping::proto::Submap* proto,
+               bool include_probability_grid_data) const override;
   void UpdateFromProto(const mapping::proto::Submap& proto) override;
 
   const HybridGrid& high_resolution_hybrid_grid() const {
diff --git a/cartographer/mapping_3d/submaps_test.cc b/cartographer/mapping_3d/submaps_test.cc
index bb48762..36776bc 100644
--- a/cartographer/mapping_3d/submaps_test.cc
+++ b/cartographer/mapping_3d/submaps_test.cc
@@ -28,7 +28,7 @@ TEST(SubmapsTest, ToFromProto) {
                         transform::Rigid3d(Eigen::Vector3d(1., 2., 0.),
                                            Eigen::Quaterniond(0., 0., 0., 1.)));
   mapping::proto::Submap proto;
-  expected.ToProto(&proto);
+  expected.ToProto(&proto, true /* include_probability_grid_data */);
   EXPECT_FALSE(proto.has_submap_2d());
   EXPECT_TRUE(proto.has_submap_3d());
   const auto actual = Submap(proto.submap_3d());