diff --git a/mmselfsup/utils/collect.py b/mmselfsup/utils/collect.py
index 26837e036..6277219b7 100644
--- a/mmselfsup/utils/collect.py
+++ b/mmselfsup/utils/collect.py
@@ -22,8 +22,8 @@ def nondist_forward_collect(func, data_loader, length):
         results_all (dict(np.ndarray)): The concatenated outputs.
     """
     results = []
-    prog_bar = mmcv.ProgressBar(len(data_loader))
-    for i, data in enumerate(data_loader):
+    prog_bar = mmcv.ProgressBar(len(data_loader.dataset))
+    for i, data in enumerate(data_loader.dataset):
         input_data = dict(img=data['img'])
         with torch.no_grad():
             result = func(**input_data)  # feat_dict
@@ -58,8 +58,8 @@ def dist_forward_collect(func, data_loader, rank, length, ret_rank=-1):
     """
     results = []
     if rank == 0:
-        prog_bar = mmcv.ProgressBar(len(data_loader))
-    for idx, data in enumerate(data_loader):
+        prog_bar = mmcv.ProgressBar(len(data_loader.dataset))
+    for idx, data in enumerate(data_loader.dataset):
         with torch.no_grad():
             result = func(**data)  # dict{key: tensor}
         results.append(result)