diff --git a/src/user/user_mesh.cc b/src/user/user_mesh.cc
index 94000819..34e29119 100644
--- a/src/user/user_mesh.cc
+++ b/src/user/user_mesh.cc
@@ -220,6 +220,10 @@ void mjCMesh::PointToLocal() {
 
 
 void mjCMesh::NameSpace(const mjCModel* m) {
+  if (name.empty()) {
+    std::string stripped = mjuu_strippath(spec_file_);
+    name = mjuu_stripext(stripped);
+  }
   mjCBase::NameSpace(m);
   if (modelfiledir_.empty()) {
     modelfiledir_ = FilePath(m->spec_modelfiledir_);
@@ -252,6 +256,12 @@ void mjCMesh::CopyFromSpec() {
   szgraph_ = 0;
   center_ = NULL;
   graph_ = NULL;
+
+  // use filename if name is missing
+  if (name.empty()) {
+    std::string stripped = mjuu_strippath(file_);
+    name = mjuu_stripext(stripped);
+  }
 }
 
 
@@ -2034,6 +2044,11 @@ void mjCSkin::PointToLocal() {
 
 
 void mjCSkin::NameSpace(const mjCModel* m) {
+  // use filename if name is missing
+  if (name.empty()) {
+    std::string stripped = mjuu_strippath(spec_file_);
+    name = mjuu_stripext(stripped);
+  }
   for (auto& name : spec_bodyname_) {
     name = m->prefix + name + m->suffix;
   }
@@ -2059,6 +2074,12 @@ void mjCSkin::CopyFromSpec() {
   bindquat_ = spec_bindquat_;
   vertid_ = spec_vertid_;
   vertweight_ = spec_vertweight_;
+
+  // use filename if name is missing
+  if (name.empty()) {
+    std::string stripped = mjuu_strippath(file_);
+    name = mjuu_stripext(stripped);
+  }
 }
 
 
diff --git a/src/user/user_model.cc b/src/user/user_model.cc
index c5e650b2..13679ef9 100644
--- a/src/user/user_model.cc
+++ b/src/user/user_model.cc
@@ -1428,23 +1428,6 @@ void mjCModel::IndexAssets(bool discard) {
 
 
 
-// if asset name is missing, set to filename
-template <typename T>
-void mjCModel::SetDefaultNames(std::vector<T*>& assets) {
-  string stripped;
-
-  // use filename if name is missing
-  for (int i=0; i<assets.size(); i++) {
-    assets[i]->CopyFromSpec();
-    if (assets[i]->name.empty()) {
-      stripped = mjuu_strippath(assets[i]->File());
-      assets[i]->name = mjuu_stripext(stripped);
-    }
-  }
-}
-
-
-
 // throw error if a name is missing
 void mjCModel::CheckEmptyNames(void) {
   // meshes
@@ -3772,10 +3755,10 @@ void mjCModel::TryCompile(mjModel*& m, mjData*& d, const mjVFS* vfs) {
   MakeLists(bodies_[0]);
 
   // fill missing names and check that they are all filled
-  SetDefaultNames(meshes_);
-  SetDefaultNames(skins_);
-  SetDefaultNames(hfields_);
-  SetDefaultNames(textures_);
+  for (const auto& asset : meshes_) asset->CopyFromSpec();
+  for (const auto& asset : skins_) asset->CopyFromSpec();
+  for (const auto& asset : hfields_) asset->CopyFromSpec();
+  for (const auto& asset : textures_) asset->CopyFromSpec();
   CheckEmptyNames();
 
   // create pending keyframes
diff --git a/src/user/user_model.h b/src/user/user_model.h
index f3607c7f..88bcd9ee 100644
--- a/src/user/user_model.h
+++ b/src/user/user_model.h
@@ -279,9 +279,6 @@ class mjCModel : public mjCModel_, private mjSpec {
   // multi-threaded mesh compilation
   void CompileMeshes(const mjVFS* vfs);
 
-  // if asset name is missing, set to filename
-  template<class T> void SetDefaultNames(std::vector<T*>& assets);
-
   // delete material from object
   template <class T> void DeleteMaterial(std::vector<T*>& list,
                                          std::string_view name = "");
diff --git a/src/user/user_objects.cc b/src/user/user_objects.cc
index 441e0c12..aa37a895 100644
--- a/src/user/user_objects.cc
+++ b/src/user/user_objects.cc
@@ -3399,11 +3399,22 @@ void mjCHField::CopyFromSpec() {
     nrow = 0;
     ncol = 0;
   }
+
+  // use filename if name is missing
+  if (name.empty()) {
+    std::string stripped = mjuu_strippath(file_);
+    name = mjuu_stripext(stripped);
+  }
 }
 
 
 
 void mjCHField::NameSpace(const mjCModel* m) {
+  // use filename if name is missing
+  if (name.empty()) {
+    std::string stripped = mjuu_strippath(spec_file_);
+    name = mjuu_stripext(stripped);
+  }
   mjCBase::NameSpace(m);
   if (modelfiledir_.empty()) {
     modelfiledir_ = FilePath(m->spec_modelfiledir_);
@@ -3648,11 +3659,22 @@ void mjCTexture::CopyFromSpec() {
     // clear precompiled asset. TODO: use asset cache
     data_.clear();
   }
+
+  // use filename if name is missing
+  if (name.empty()) {
+    std::string stripped = mjuu_strippath(file_);
+    name = mjuu_stripext(stripped);
+  }
 }
 
 
 
 void mjCTexture::NameSpace(const mjCModel* m) {
+  // use filename if name is missing
+  if (name.empty()) {
+    std::string stripped = mjuu_strippath(spec_file_);
+    name = mjuu_stripext(stripped);
+  }
   mjCBase::NameSpace(m);
   if (modelfiledir_.empty()) {
     modelfiledir_ = FilePath(m->spec_modelfiledir_);
diff --git a/test/user/user_api_test.cc b/test/user/user_api_test.cc
index bb084d6c..cdad61b3 100644
--- a/test/user/user_api_test.cc
+++ b/test/user/user_api_test.cc
@@ -1156,5 +1156,43 @@ TEST_F(MujocoTest, AttachMocap) {
   mj_deleteModel(m_expected);
 }
 
+TEST_F(MujocoTest, AttachUnnamedAssets) {
+  static constexpr char cube[] = R"(
+  v -1 -1  1
+  v  1 -1  1
+  v -1  1  1
+  v  1  1  1
+  v -1  1 -1
+  v  1  1 -1
+  v -1 -1 -1
+  v  1 -1 -1)";
+
+  auto vfs = std::make_unique<mjVFS>();
+  mj_defaultVFS(vfs.get());
+  mj_addBufferVFS(vfs.get(), "cube.obj", cube, sizeof(cube));
+
+  mjSpec* child = mj_makeSpec();
+  mjsMesh* mesh = mjs_addMesh(child, 0);
+  mjsFrame* frame = mjs_addFrame(mjs_findBody(child, "world"), 0);
+  mjsGeom* geom = mjs_addGeom(mjs_findBody(child, "world"), 0);
+  mjs_setFrame(geom->element, frame);
+  mjs_setString(mesh->file, "cube.obj");
+  mjs_setString(geom->meshname, "cube");
+  geom->type = mjGEOM_MESH;
+
+  mjSpec* spec = mj_makeSpec();
+  mjs_attachFrame(mjs_findBody(spec, "world"), frame, "_", "");
+
+  mjModel* model = mj_compile(spec, vfs.get());
+  EXPECT_THAT(model, NotNull());
+  EXPECT_THAT(model->nmesh, 1);
+  EXPECT_STREQ(mj_id2name(model, mjOBJ_MESH, 0), "_cube");
+
+  mj_deleteVFS(vfs.get());
+  mj_deleteSpec(child);
+  mj_deleteSpec(spec);
+  mj_deleteModel(model);
+}
+
 }  // namespace
 }  // namespace mujoco