diff --git a/mmedit/models/editors/ddpm/denoising_unet.py b/mmedit/models/editors/ddpm/denoising_unet.py
index 461758c178..872783e3d5 100644
--- a/mmedit/models/editors/ddpm/denoising_unet.py
+++ b/mmedit/models/editors/ddpm/denoising_unet.py
@@ -1117,7 +1117,7 @@ def __init__(self,
                 mmengine.print_log('\'SiLU\' is not supported for '
                                    f'torch < 1.6.0, found \'{torch.version}\'.'
                                    'Use ReLu instead but result maybe wrong')
-                self.conv_act == nn.ReLU()
+                self.conv_act = nn.ReLU()
             self.conv_out = nn.Conv2d(
                 block_out_channels[0],
                 self.out_channels,
diff --git a/tests/test_models/test_editors/test_stable_diffusion/test_stable_diffusion.py b/tests/test_models/test_editors/test_stable_diffusion/test_stable_diffusion.py
index fb2fe3352d..f84f58a7ee 100644
--- a/tests/test_models/test_editors/test_stable_diffusion/test_stable_diffusion.py
+++ b/tests/test_models/test_editors/test_stable_diffusion/test_stable_diffusion.py
@@ -1,6 +1,5 @@
 # Copyright (c) OpenMMLab. All rights reserved.
 import platform
-import sys
 
 import pytest
 import torch
@@ -102,8 +101,6 @@ def __call__(self, x, attention_mask):
 @pytest.mark.skipif(
     'win' in platform.system().lower(),
     reason='skip on windows due to limited RAM.')
-@pytest.mark.skipif(
-    sys.version_info < (3, 8), reason='skip because python version is old.')
 def test_stable_diffusion():
     StableDiffuser = MODELS.build(Config(model))
     StableDiffuser.tokenizer = dummy_tokenizer()