diff --git a/demos/demo_fit_body.py b/demos/demo_fit_body.py
index 8c248da..b6097e2 100644
--- a/demos/demo_fit_body.py
+++ b/demos/demo_fit_body.py
@@ -99,7 +99,7 @@ def main(args):
             visualizer.rotate_results(opdict, visdict=visdict, savepath=os.path.join(savefolder, f'{name}_vis.gif'))
         if args.saveObj:
             visualizer.save_obj(os.path.join(savefolder, name, f'{name}.obj'), opdict)
-        if args.saveParam:
+        if args.saveParam and batch['bbox'] is not None:
             codedict['bbox'] = batch['bbox']
             util.save_pkl(os.path.join(savefolder, name, f'{name}_param.pkl'), codedict)
             np.savetxt(os.path.join(savefolder, name, f'{name}_bbox.txt'), batch['bbox'].squeeze())
diff --git a/pixielib/datasets/detectors.py b/pixielib/datasets/detectors.py
index 7f00803..3c2a029 100644
--- a/pixielib/datasets/detectors.py
+++ b/pixielib/datasets/detectors.py
@@ -51,7 +51,7 @@ def run(self, input):
         '''
         prediction = self.model(input.to(self.device))[0]
         inds = (prediction['labels']==1)*(prediction['scores']>0.5)
-        if len(inds) < 1:
+        if len(inds) < 1 or len(prediction['boxes'][inds]) < 1:
             return None
         else:
             bbox = prediction['boxes'][inds][0].cpu().numpy()