diff --git a/libretranslate/init.py b/libretranslate/init.py
index 098cb20..0df8ba3 100644
--- a/libretranslate/init.py
+++ b/libretranslate/init.py
@@ -27,6 +27,8 @@ def check_and_install_models(force=False, load_only_lang_codes=None,update=False
         print("Found %s models" % len(available_packages))
         if load_only_lang_codes is not None:
             # load_only_lang_codes: List[str] (codes)
+            load_only_lang_codes = libretranslate.language.iso2model(load_only_lang_codes)
+
             # Ensure the user does not use any unavailable language code.
             unavailable_lang_codes = set(load_only_lang_codes)
             for pack in available_packages:
diff --git a/libretranslate/language.py b/libretranslate/language.py
index 7383c74..42f8866 100644
--- a/libretranslate/language.py
+++ b/libretranslate/language.py
@@ -14,6 +14,9 @@ aliases = {
 rev_aliases = {v.lower(): k for k, v in aliases.items()}
 
 def iso2model(lang):
+    if isinstance(lang, list):
+        return [iso2model(l) for l in lang]
+    
     if not isinstance(lang, str):
         return lang