diff --git a/mmdet/apis/inference.py b/mmdet/apis/inference.py
index 222fc8319f1d2d07c4cfdfd7a246131b649489cc..c8c37edcd1f9e00f23a0d32bbd2a0f4c367de041 100644
--- a/mmdet/apis/inference.py
+++ b/mmdet/apis/inference.py
@@ -34,7 +34,7 @@ def init_detector(config, checkpoint=None, device='cuda:0'):
     if checkpoint is not None:
         checkpoint = load_checkpoint(model, checkpoint)
         if 'CLASSES' in checkpoint['meta']:
-            model.CLASSES = checkpoint['meta']['classes']
+            model.CLASSES = checkpoint['meta']['CLASSES']
         else:
             warnings.warn('Class names are not saved in the checkpoint\'s '
                           'meta data, use COCO classes by default.')
diff --git a/tools/train.py b/tools/train.py
index 3e06d6f56cd6109f6788e84fd7284a852809a612..b8f21d11fa687ffd4e9c5aaf8b5d46b5142c826e 100644
--- a/tools/train.py
+++ b/tools/train.py
@@ -79,7 +79,7 @@ def main():
         cfg.checkpoint_config.meta = dict(
             mmdet_version=__version__,
             config=cfg.text,
-            classes=train_dataset.CLASSES)
+            CLASSES=train_dataset.CLASSES)
     # add an attribute for visualization convenience
     model.CLASSES = train_dataset.CLASSES
     train_detector(