diff --git a/addons/io_scene_swbf_msh/msh_scene_read.py b/addons/io_scene_swbf_msh/msh_scene_read.py
index 8abd1e2..fd40d4d 100644
--- a/addons/io_scene_swbf_msh/msh_scene_read.py
+++ b/addons/io_scene_swbf_msh/msh_scene_read.py
@@ -203,7 +203,9 @@ def _read_modl(modl: Reader, materials_list: List[Material]) -> Model:
 
                 global model_counter
                 global mndx_remap
-                mndx_remap[index] = model_counter
+
+                if index not in mndx_remap:
+                    mndx_remap[index] = model_counter
 
                 model_counter += 1