diff --git a/mmdet/apis/train.py b/mmdet/apis/train.py
index 97c0dc69..9d6f5bb8 100644
--- a/mmdet/apis/train.py
+++ b/mmdet/apis/train.py
@@ -205,7 +205,10 @@ def _dist_train(model,
         for ds in dataset
     ]
     # put model on gpus
-    model = MMDistributedDataParallel(model.cuda())
+    # model = MMDistributedDataParallel(model.cuda())
+    model = MMDistributedDataParallel(model.cuda(), 
+                                      device_ids=[torch.cuda.current_device()], 
+                                      broadcast_buffers=False)
 
     # build runner
     optimizer = build_optimizer(model, cfg.optimizer)
diff --git a/requirements/runtime.txt b/requirements/runtime.txt
index 898c0e2a..a230edfc 100644
--- a/requirements/runtime.txt
+++ b/requirements/runtime.txt
@@ -1,5 +1,5 @@
 matplotlib
-mmcv>=0.2.15
+mmcv>=0.3.1
 numpy
 scipy
 # need older pillow until torchvision is fixed