diff --git a/modules/godot_physics_3d/godot_soft_body_3d.cpp b/modules/godot_physics_3d/godot_soft_body_3d.cpp
index 9c82781c80c..3f1da45b1c9 100644
--- a/modules/godot_physics_3d/godot_soft_body_3d.cpp
+++ b/modules/godot_physics_3d/godot_soft_body_3d.cpp
@@ -136,6 +136,10 @@ void GodotSoftBody3D::set_mesh(RID p_mesh) {
 		return;
 	}
 
+	// TODO: calling RenderingServer::mesh_surface_get_arrays() from the physics thread
+	// is not safe and can deadlock when physics/3d/run_on_separate_thread is enabled.
+	// This method blocks on the main thread to return data, but the main thread may be
+	// blocked waiting on us in PhysicsServer3D::sync().
 	Array arrays = RenderingServer::get_singleton()->mesh_surface_get_arrays(soft_mesh, 0);
 	ERR_FAIL_COND(arrays.is_empty());
 
diff --git a/modules/jolt_physics/objects/jolt_soft_body_3d.cpp b/modules/jolt_physics/objects/jolt_soft_body_3d.cpp
index 95bd39b5a39..9813124eb86 100644
--- a/modules/jolt_physics/objects/jolt_soft_body_3d.cpp
+++ b/modules/jolt_physics/objects/jolt_soft_body_3d.cpp
@@ -128,6 +128,10 @@ bool JoltSoftBody3D::_ref_shared_data() {
 	if (iter_shared_data == mesh_to_shared.end()) {
 		RenderingServer *rendering = RenderingServer::get_singleton();
 
+		// TODO: calling RenderingServer::mesh_surface_get_arrays() from the physics thread
+		// is not safe and can deadlock when physics/3d/run_on_separate_thread is enabled.
+		// This method blocks on the main thread to return data, but the main thread may be
+		// blocked waiting on us in PhysicsServer3D::sync().
 		const Array mesh_data = rendering->mesh_surface_get_arrays(mesh, 0);
 		ERR_FAIL_COND_V(mesh_data.is_empty(), false);