diff --git a/vllm/parser/parser_manager.py b/vllm/parser/parser_manager.py
index 5577dfb1d8..f8bded62d5 100644
--- a/vllm/parser/parser_manager.py
+++ b/vllm/parser/parser_manager.py
@@ -158,7 +158,7 @@ class ParserManager:
 
             if isinstance(name, str):
                 names = [name]
-            elif is_list_of(name, str):
+            elif name is not None and is_list_of(name, str):
                 names = name
             else:
                 names = [class_name]