diff --git a/pytorch_lightning/trainer/configuration_validator.py b/pytorch_lightning/trainer/configuration_validator.py
index f4144563a7..d910701fa3 100644
--- a/pytorch_lightning/trainer/configuration_validator.py
+++ b/pytorch_lightning/trainer/configuration_validator.py
@@ -10,7 +10,7 @@ class ConfigValidator(object):
 
     def enforce_datamodule_dataloader_override(self, train_dataloader, val_dataloaders, datamodule):
         # If you supply a datamodule you can't supply train_dataloader or val_dataloaders
-        if (train_dataloader or val_dataloaders) and datamodule:
+        if (train_dataloader is not None or val_dataloaders is not None) and datamodule is not None:
             raise MisconfigurationException(
                 'You cannot pass train_dataloader or val_dataloaders to trainer.fit if you supply a datamodule'
             )