diff --git a/openhands/core/main.py b/openhands/core/main.py
index a5192b9c5f..3c8efe38ab 100644
--- a/openhands/core/main.py
+++ b/openhands/core/main.py
@@ -247,17 +247,18 @@ if __name__ == '__main__':
     # Read task from file, CLI args, or stdin
     task_str = read_task(args, config.cli_multiline_input)
 
+    initial_user_action: Action = NullAction()
     if config.replay_trajectory_path:
         if task_str:
             raise ValueError(
                 'User-specified task is not supported under trajectory replay mode'
             )
+    else:
+        if not task_str:
+            raise ValueError('No task provided. Please specify a task through -t, -f.')
 
-    if not task_str:
-        raise ValueError('No task provided. Please specify a task through -t, -f.')
-
-    # Create initial user action
-    initial_user_action: MessageAction = MessageAction(content=task_str)
+        # Create actual initial user action
+        initial_user_action = MessageAction(content=task_str)
 
     # Set session name
     session_name = args.name