diff --git a/applications/ColossalChat/coati/distributed/launch.py b/applications/ColossalChat/coati/distributed/launch.py
index 30e7382ef..dc8bf0057 100644
--- a/applications/ColossalChat/coati/distributed/launch.py
+++ b/applications/ColossalChat/coati/distributed/launch.py
@@ -16,7 +16,7 @@ def get_jsonl_size_fast(path: str) -> int:
     with open(path) as f:
         lines = f.readlines()
         lines = [line for line in lines if line.strip()]
-        return len(lines) - 1
+        return len(lines)
 
 
 def get_dp_size_fast(n_procs: int, plugin_config: Dict[str, Any]) -> int: