diff --git a/vllm/entrypoints/chat_utils.py b/vllm/entrypoints/chat_utils.py
index e3510d2e903..9c7196d7b0e 100644
--- a/vllm/entrypoints/chat_utils.py
+++ b/vllm/entrypoints/chat_utils.py
@@ -753,7 +753,7 @@ def build_video_prompts_from_mm_data(
                 video_prompts_dict[video_idx].append(prompt)
         elif hasattr(item, "type") and getattr(item, "type", None) == "video_chunk":
             video_idx = getattr(item, "video_idx", 0)
-            prompt = getattr(item, "prompt", None) or ""
+            prompt = getattr(item, "prompt", "")
             video_prompts_dict[video_idx].append(prompt)
 
     # Build prompts in video order