diff --git a/pytorch_lightning/trainer/data_loading.py b/pytorch_lightning/trainer/data_loading.py
index b3e15024c45de..fb82c70b31bb5 100644
--- a/pytorch_lightning/trainer/data_loading.py
+++ b/pytorch_lightning/trainer/data_loading.py
@@ -219,7 +219,7 @@ def _reset_eval_dataloader(self, model: LightningModule, mode: str) -> Tuple[int
                     ' this off for validation and test dataloaders.')
 
         # add samplers
-        dataloaders = [self.auto_add_sampler(dl, train=False) for dl in dataloaders if dl]
+        dataloaders = [self.auto_add_sampler(dl, train=False) for dl in dataloaders if dl is not None]
 
         num_batches = 0