diff --git a/pytorch_lightning/models/trainer.py b/pytorch_lightning/models/trainer.py
index ad7b9ebe59..3b78306af3 100644
--- a/pytorch_lightning/models/trainer.py
+++ b/pytorch_lightning/models/trainer.py
@@ -277,7 +277,7 @@ class Trainer(TrainerIO):
         self.test_dataloader = model.test_dataloader
         self.val_dataloader = model.val_dataloader
 
-        if self.data_parallel and not issubclass(self.tng_dataloader.sampler, DistributedSampler):
+        if self.data_parallel and not isinstance(self.tng_dataloader.sampler, DistributedSampler):
             msg = '''
             when using multiple gpus and multiple nodes you must pass a DistributedSampler to DataLoader(sampler).