diff --git a/data/coco.py b/data/coco.py
index 765531761..a5615209b 100644
--- a/data/coco.py
+++ b/data/coco.py
@@ -14,7 +14,7 @@
 COCO_API = 'PythonAPI'
 INSTANCES_SET = 'instances_{}.json'
 COCO_CLASSES = ('person', 'bicycle', 'car', 'motorcycle', 'airplane', 'bus',
-                'train', 'truck', 'boat', 'traffic light', 'fire', 'hydrant',
+                'train', 'truck', 'boat', 'traffic light', 'fire hydrant',
                 'stop sign', 'parking meter', 'bench', 'bird', 'cat', 'dog',
                 'horse', 'sheep', 'cow', 'elephant', 'bear', 'zebra',
                 'giraffe', 'backpack', 'umbrella', 'handbag', 'tie',
@@ -25,7 +25,7 @@
                 'sandwich', 'orange', 'broccoli', 'carrot', 'hot dog', 'pizza',
                 'donut', 'cake', 'chair', 'couch', 'potted plant', 'bed',
                 'dining table', 'toilet', 'tv', 'laptop', 'mouse', 'remote',
-                'keyboard', 'cell phone', 'microwave oven', 'toaster', 'sink',
+                'keyboard', 'cell phone', 'microwave', 'oven', 'toaster', 'sink',
                 'refrigerator', 'book', 'clock', 'vase', 'scissors',
                 'teddy bear', 'hair drier', 'toothbrush')
 
diff --git a/data/config.py b/data/config.py
index 8999622cc..e16659c7f 100644
--- a/data/config.py
+++ b/data/config.py
@@ -27,7 +27,7 @@
 }
 
 coco = {
-    'num_classes': 201,
+    'num_classes': 81,
     'lr_steps': (280000, 360000, 400000),
     'max_iter': 400000,
     'feature_maps': [38, 19, 10, 5, 3, 1],