diff --git a/flagai/model/aquila2/modeling_aquila.py b/flagai/model/aquila2/modeling_aquila.py
index ea1083cc..2ebe79af 100755
--- a/flagai/model/aquila2/modeling_aquila.py
+++ b/flagai/model/aquila2/modeling_aquila.py
@@ -923,7 +923,7 @@ def predict(self, text, tokenizer=None,
                 sft=True, convo_template = "",
                 device = "cuda",
                 model_name="AquilaChat2-7B",
-                history=[],
+                history=None,
                 **kwargs):
 
         vocab = tokenizer.get_vocab()
@@ -1033,9 +1033,10 @@ def predict(self, text, tokenizer=None,
             convert_tokens = convert_tokens[1:]
             probs = probs[1:]
 
-        # Update history
-        history.insert(0, ('ASSISTANT', out))
-        history.insert(0, ('USER', text))
+        if isinstance(history, list):
+          # Update history
+          history.insert(0, ('ASSISTANT', out))
+          history.insert(0, ('USER', text))
 
         return out 
 
diff --git a/flagai/model/aquila2/utils.py b/flagai/model/aquila2/utils.py
index 7e740c45..054db0d8 100755
--- a/flagai/model/aquila2/utils.py
+++ b/flagai/model/aquila2/utils.py
@@ -21,6 +21,9 @@ def covert_prompt_to_input_ids_with_history(text, history, tokenizer, max_token,
 
     example = tokenizer.encode_plus(f"{conv.get_prompt()} ", None, max_length=None)['input_ids']
 
+    if history is None or not isinstance(history, list):
+      history = []
+
     while(len(history) > 0 and (len(example) < max_token)):
         tmp = history.pop()
         if tmp[0] == 'ASSISTANT':
@@ -35,4 +38,4 @@ def covert_prompt_to_input_ids_with_history(text, history, tokenizer, max_token,
     print('model in:', conv.get_prompt())
     example = tokenizer.encode_plus(f"{conv.get_prompt()} ", None, max_length=None)['input_ids']
 
-    return example
\ No newline at end of file
+    return example
diff --git a/flagai/model/aquila2_hf/predict.py b/flagai/model/aquila2_hf/predict.py
index b2d19c8b..2e5143f4 100644
--- a/flagai/model/aquila2_hf/predict.py
+++ b/flagai/model/aquila2_hf/predict.py
@@ -310,6 +310,9 @@ def covert_prompt_to_input_ids_with_history(text, history, tokenizer, max_token,
 
     example = tokenizer.encode_plus(f"{conv.get_prompt()} ", None, max_length=None)['input_ids']
 
+    if history is None or not isinstance(history, list):
+      history = []
+
     while(len(history) > 0 and (len(example) < max_token)):
         tmp = history.pop()
         if tmp[0] == 'ASSISTANT':
@@ -333,7 +336,7 @@ def predict(model, text, tokenizer=None,
             sft=True, convo_template = "",
             device = "cuda",
             model_name="AquilaChat2-7B",
-            history=[],
+            history=None,
             **kwargs):
 
     vocab = tokenizer.get_vocab()
@@ -435,8 +438,9 @@ def predict(model, text, tokenizer=None,
         convert_tokens = convert_tokens[1:]
         probs = probs[1:]
 
-    # Update history
-    history.insert(0, ('ASSISTANT', out))
-    history.insert(0, ('USER', text))
+    if isinstance(history, list):
+        # Update history
+        history.insert(0, ('ASSISTANT', out))
+        history.insert(0, ('USER', text))
 
     return out