diff --git a/python/llm/src/bigdl/llm/transformers/convert.py b/python/llm/src/bigdl/llm/transformers/convert.py
index 8529a7f0..6d03a55d 100644
--- a/python/llm/src/bigdl/llm/transformers/convert.py
+++ b/python/llm/src/bigdl/llm/transformers/convert.py
@@ -181,7 +181,7 @@ def optimize(model):
         # todo implement 4.28.0 ~ 4.30.2
         pass
 
-    if model.config.architectures[0] == "ChatGLMModel":
+    if model.config.architectures is not None and model.config.architectures[0] == "ChatGLMModel":
         if model.config.num_layers == 28 and hasattr(model.config, 'rope_ratio'):
             # chatglm2-6b-32k
             modeling_module_name = model.__class__.__module__