diff --git a/doc/includes/references.h b/doc/includes/references.h
index 0f27ccf0..094931fb 100644
--- a/doc/includes/references.h
+++ b/doc/includes/references.h
@@ -2119,6 +2119,7 @@ typedef struct mjsMesh_ {          // mesh specification
   double scale[3];                 // rescale mesh
   mjtMeshInertia inertia;          // inertia type (convex, legacy, exact, shell)
   mjtByte smoothnormal;            // do not exclude large-angle faces from normals
+  mjtByte needsdf;                 // compute sdf from mesh
   int maxhullvert;                 // maximum vertex count for the convex hull
   mjFloatVec* uservert;            // user vertex data
   mjFloatVec* usernormal;          // user normal data
diff --git a/include/mujoco/mjspec.h b/include/mujoco/mjspec.h
index 138b1937..08f8a328 100644
--- a/include/mujoco/mjspec.h
+++ b/include/mujoco/mjspec.h
@@ -462,6 +462,7 @@ typedef struct mjsMesh_ {          // mesh specification
   double scale[3];                 // rescale mesh
   mjtMeshInertia inertia;          // inertia type (convex, legacy, exact, shell)
   mjtByte smoothnormal;            // do not exclude large-angle faces from normals
+  mjtByte needsdf;                 // compute sdf from mesh
   int maxhullvert;                 // maximum vertex count for the convex hull
   mjFloatVec* uservert;            // user vertex data
   mjFloatVec* usernormal;          // user normal data
diff --git a/python/mujoco/introspect/structs.py b/python/mujoco/introspect/structs.py
index 82137c3b..7dea2be0 100644
--- a/python/mujoco/introspect/structs.py
+++ b/python/mujoco/introspect/structs.py
@@ -9388,6 +9388,11 @@ STRUCTS: Mapping[str, StructDecl] = dict([
                  type=ValueType(name='mjtByte'),
                  doc='do not exclude large-angle faces from normals',
              ),
+             StructFieldDecl(
+                 name='needsdf',
+                 type=ValueType(name='mjtByte'),
+                 doc='compute sdf from mesh',
+             ),
              StructFieldDecl(
                  name='maxhullvert',
                  type=ValueType(name='int'),
diff --git a/src/user/user_mesh.cc b/src/user/user_mesh.cc
index 897b5164..a84a9220 100644
--- a/src/user/user_mesh.cc
+++ b/src/user/user_mesh.cc
@@ -140,7 +140,6 @@ mjCMesh::mjCMesh(mjCModel* _model, mjCDef* _def) {
   maxhullvert_ = -1;
   processed_ = false;
   visual_ = true;
-  needoct_ = false;
   needreorient_ = true;
 
   // reset to default if given
@@ -362,7 +361,7 @@ void mjCMesh::LoadSDF() {
   }
 
   needreorient_ = false;
-  needoct_ = false;
+  needsdf = false;
   normal_ = std::move(usernormal);
   face_ = std::move(userface);
   ProcessVertices(uservert);
@@ -685,7 +684,7 @@ void mjCMesh::TryCompile(const mjVFS* vfs) {
   }
 
   // make octree
-  if (!needoct_) {
+  if (!needsdf) {
     octree_.Clear();  // this occurs when a non-SDF mesh is loaded from a cached SDF mesh
   } else if (octree_.Nodes().empty()) {
     octree_.SetFace(vert_, face_);
diff --git a/src/user/user_model.cc b/src/user/user_model.cc
index 257b6524..03132736 100644
--- a/src/user/user_model.cc
+++ b/src/user/user_model.cc
@@ -1689,7 +1689,7 @@ void mjCModel::IndexAssets(bool discard) {
           ((mjCMesh*)mesh)->SetNotVisual();  // reset to true by mesh->Compile()
         }
         geom->mesh = (discard && geom->visual_) ? nullptr : (mjCMesh*)mesh;
-        static_cast<mjCMesh*>(mesh)->needoct_ |= geom->spec.type == mjGEOM_SDF;
+        static_cast<mjCMesh*>(mesh)->spec.needsdf |= geom->spec.type == mjGEOM_SDF;
       } else {
         throw mjCError(geom, "mesh '%s' not found in geom %d", geom->get_meshname().c_str(), i);
       }
diff --git a/src/user/user_objects.h b/src/user/user_objects.h
index 3060bf6c..aa3528fa 100644
--- a/src/user/user_objects.h
+++ b/src/user/user_objects.h
@@ -1004,7 +1004,6 @@ class mjCMesh_ : public mjCBase {
 
   // used by the compiler
   bool needreorient_;                            // needs reorientation
-  bool needoct_;                                 // needs octree
   bool visual_;                                  // true: the mesh is only visual
   std::vector< std::pair<int, int> > halfedge_;  // half-edge data