diff --git a/mmcv/cnn/bricks/conv.py b/mmcv/cnn/bricks/conv.py
index e9f4712027a..a00b0a52cee 100644
--- a/mmcv/cnn/bricks/conv.py
+++ b/mmcv/cnn/bricks/conv.py
@@ -1,4 +1,5 @@
 # Copyright (c) OpenMMLab. All rights reserved.
+import inspect
 from typing import Dict, Optional
 
 from mmengine.registry import MODELS
@@ -35,8 +36,8 @@ def build_conv_layer(cfg: Optional[Dict], *args, **kwargs) -> nn.Module:
         cfg_ = cfg.copy()
 
     layer_type = cfg_.pop('type')
-    if isinstance(layer_type, type):
-        return layer_type(*args, **kwargs, **cfg_)
+    if inspect.isclass(layer_type):
+        return layer_type(*args, **kwargs, **cfg_)  # type: ignore
     # Switch registry to the target scope. If `conv_layer` cannot be found
     # in the registry, fallback to search `conv_layer` in the
     # mmengine.MODELS.
diff --git a/mmcv/cnn/bricks/padding.py b/mmcv/cnn/bricks/padding.py
index a27cb688b28..3b29996b94a 100644
--- a/mmcv/cnn/bricks/padding.py
+++ b/mmcv/cnn/bricks/padding.py
@@ -1,4 +1,5 @@
 # Copyright (c) OpenMMLab. All rights reserved.
+import inspect
 from typing import Dict
 
 import torch.nn as nn
@@ -27,7 +28,7 @@ def build_padding_layer(cfg: Dict, *args, **kwargs) -> nn.Module:
 
     cfg_ = cfg.copy()
     padding_type = cfg_.pop('type')
-    if isinstance(padding_type, type):
+    if inspect.isclass(padding_type):
         return padding_type(*args, **kwargs, **cfg_)
     # Switch registry to the target scope. If `padding_layer` cannot be found
     # in the registry, fallback to search `padding_layer` in the
diff --git a/mmcv/cnn/bricks/upsample.py b/mmcv/cnn/bricks/upsample.py
index 5d0c4735882..a9ed51b6b99 100644
--- a/mmcv/cnn/bricks/upsample.py
+++ b/mmcv/cnn/bricks/upsample.py
@@ -1,4 +1,5 @@
 # Copyright (c) OpenMMLab. All rights reserved.
+import inspect
 from typing import Dict
 
 import torch
@@ -76,7 +77,7 @@ def build_upsample_layer(cfg: Dict, *args, **kwargs) -> nn.Module:
 
     layer_type = cfg_.pop('type')
 
-    if isinstance(layer_type, type):
+    if inspect.isclass(layer_type):
         upsample = layer_type
     # Switch registry to the target scope. If `upsample` cannot be found
     # in the registry, fallback to search `upsample` in the
diff --git a/tests/test_cnn/test_build_layers.py b/tests/test_cnn/test_build_layers.py
index 363bcfcaa96..eefdd640ca7 100644
--- a/tests/test_cnn/test_build_layers.py
+++ b/tests/test_cnn/test_build_layers.py
@@ -1,4 +1,5 @@
 # Copyright (c) OpenMMLab. All rights reserved.
+import inspect
 from importlib import import_module
 
 import numpy as np
@@ -190,7 +191,7 @@ def test_build_activation_layer():
     for module_name in ['activation', 'hsigmoid', 'hswish', 'swish']:
         act_module = import_module(f'mmcv.cnn.bricks.{module_name}')
         for key, value in act_module.__dict__.items():
-            if isinstance(value, type) and issubclass(value, nn.Module):
+            if inspect.isclass(value) and issubclass(value, nn.Module):
                 act_names.append(key)
 
     with pytest.raises(TypeError):
@@ -235,7 +236,7 @@ def test_build_padding_layer():
     for module_name in ['padding']:
         pad_module = import_module(f'mmcv.cnn.bricks.{module_name}')
         for key, value in pad_module.__dict__.items():
-            if isinstance(value, type) and issubclass(value, nn.Module):
+            if inspect.isclass(value) and issubclass(value, nn.Module):
                 pad_names.append(key)
 
     with pytest.raises(TypeError):