diff --git a/src/icesat2_tracks/analysis_db/B01_SL_load_single_file.py b/src/icesat2_tracks/analysis_db/B01_SL_load_single_file.py
index 1cf34556..168f7956 100644
--- a/src/icesat2_tracks/analysis_db/B01_SL_load_single_file.py
+++ b/src/icesat2_tracks/analysis_db/B01_SL_load_single_file.py
@@ -89,7 +89,7 @@ def run_B01_SL_load_single_file(
     batch_key: str = typer.Option(..., callback=validate_batch_key),
     ID_flag: bool = True,
     plot_flag: bool = True,
-    output_dir: str = typer.Option(None, callback=validate_output_dir),
+    output_dir: str = typer.Option(..., callback=validate_output_dir),
     verbose: bool = False
 ):
     """