diff --git a/pytorch_lightning/models/trainer.py b/pytorch_lightning/models/trainer.py
index 434e5060..241b2401 100644
--- a/pytorch_lightning/models/trainer.py
+++ b/pytorch_lightning/models/trainer.py
@@ -268,6 +268,7 @@ class Trainer(TrainerIO):
 
         # put on gpu if needed
         if self.on_gpu:
+            model.cuda()
             model = LightningDataParallel(model, device_ids=self.data_parallel_device_ids)
 
         # run tiny validation to make sure program won't crash during val