diff --git a/aosstower/level_b1/quicklook.py b/aosstower/level_b1/quicklook.py
index 7ba728a1441979218a77fc98e872ac74e6671593..73f9cc157c5deae7e5787c02bde130bc9eeb83d5 100644
--- a/aosstower/level_b1/quicklook.py
+++ b/aosstower/level_b1/quicklook.py
@@ -431,7 +431,7 @@ def create_plot(plot_names, frame, output, start_time=None, end_time=None, thumb
             out_path = Path(out_fn)
             stem = out_path.stem
             ext = out_path.suffix
-            out_fn = f"{stem}_thumbnail{ext}"
+            out_fn = out_path.parent / f"{stem}_thumbnail{ext}"
             plot_maker.convert_to_thumbnail(fig)
             LOG.info(f"Saving thumbnail '{name}' to filename '{out_fn}'")
             fig.savefig(out_fn)