diff --git a/mmcv/ops/cc_attention.py b/mmcv/ops/cc_attention.py
index 6f59d29fd..53efff9e6 100644
--- a/mmcv/ops/cc_attention.py
+++ b/mmcv/ops/cc_attention.py
@@ -3,7 +3,7 @@ import torch.nn as nn
 import torch.nn.functional as F
 from torch.autograd.function import once_differentiable
 
-from mmcv.cnn import Scale
+from mmcv.cnn import PLUGIN_LAYERS, Scale
 from ..utils import ext_loader
 
 ext_module = ext_loader.load_ext(
@@ -66,6 +66,7 @@ ca_weight = CAWeightFunction.apply
 ca_map = CAMapFunction.apply
 
 
+@PLUGIN_LAYERS.register_module()
 class CrissCrossAttention(nn.Module):
     """Criss-Cross Attention Module."""