diff --git a/configs/_base_/models/fast_scnn.py b/configs/_base_/models/fast_scnn.py
index 5be999f00..94d6ab93e 100644
--- a/configs/_base_/models/fast_scnn.py
+++ b/configs/_base_/models/fast_scnn.py
@@ -4,8 +4,7 @@ model = dict(
     type='EncoderDecoder',
     backbone=dict(
         type='FastSCNN',
-        downsample_dw_channels1=32,
-        downsample_dw_channels2=48,
+        downsample_dw_channels=(32, 48),
         global_in_channels=64,
         global_block_channels=(64, 96, 128),
         global_out_channels=128,
diff --git a/mmseg/models/backbones/fast_scnn.py b/mmseg/models/backbones/fast_scnn.py
index d6eb23e48..dabbf6c3b 100644
--- a/mmseg/models/backbones/fast_scnn.py
+++ b/mmseg/models/backbones/fast_scnn.py
@@ -10,12 +10,11 @@ from ..builder import BACKBONES
 
 class LearningToDownsample(nn.Module):
     """Learning to downsample module.
+
     Args:
         in_channels (int): Number of input channels.
-        dw_channels1 (int): Number of output channels of the first
-            depthwise conv (dwconv) layer.
-        dw_channels2 (int): Number of output channels of the second
-            dwconv layer.
+        dw_channels (tuple): Number of output channels of the first and
+            the second depthwise conv (dwconv) layers.
         out_channels (int): Number of output channels of the whole
             'learning to downsample' module.
         conv_cfg (dict | None): Config of conv layers. Default: None
@@ -27,8 +26,7 @@ class LearningToDownsample(nn.Module):
 
     def __init__(self,
                  in_channels,
-                 dw_channels1,
-                 dw_channels2,
+                 dw_channels,
                  out_channels,
                  conv_cfg=None,
                  norm_cfg=dict(type='BN'),
@@ -37,6 +35,9 @@ class LearningToDownsample(nn.Module):
         self.conv_cfg = conv_cfg
         self.norm_cfg = norm_cfg
         self.act_cfg = act_cfg
+        dw_channels1 = dw_channels[0]
+        dw_channels2 = dw_channels[1]
+
         self.conv = ConvModule(
             in_channels,
             dw_channels1,
@@ -235,12 +236,10 @@ class FastSCNN(nn.Module):
     """Fast-SCNN Backbone.
     Args:
         in_channels (int): Number of input image channels. Default: 3.
-        downsample_dw_channels1 (int): Number of output channels after
-            the first conv layer in Learning-To-Downsample (LTD) module.
-            Default: 32.
-        downsample_dw_channels2 (int): Number of output channels
-            after the second conv layer in LTD.
-            Default: 48.
+        downsample_dw_channels (tuple): Number of output channels after
+            the first conv layer & the second conv layer in
+            Learning-To-Downsample (LTD) module.
+            Default: (32, 48).
         global_in_channels (int): Number of input channels of
             Global Feature Extractor(GFE).
             Equal to number of output channels of LTD.
@@ -280,8 +279,7 @@ class FastSCNN(nn.Module):
 
     def __init__(self,
                  in_channels=3,
-                 downsample_dw_channels1=32,
-                 downsample_dw_channels2=48,
+                 downsample_dw_channels=(32, 48),
                  global_in_channels=64,
                  global_block_channels=(64, 96, 128),
                  global_out_channels=128,
@@ -307,8 +305,8 @@ class FastSCNN(nn.Module):
                             downsampling factor in the GFE module!')
 
         self.in_channels = in_channels
-        self.downsample_dw_channels1 = downsample_dw_channels1
-        self.downsample_dw_channels2 = downsample_dw_channels2
+        self.downsample_dw_channels1 = downsample_dw_channels[0]
+        self.downsample_dw_channels2 = downsample_dw_channels[1]
         self.global_in_channels = global_in_channels
         self.global_block_channels = global_block_channels
         self.global_out_channels = global_out_channels
@@ -323,8 +321,7 @@ class FastSCNN(nn.Module):
         self.align_corners = align_corners
         self.learning_to_downsample = LearningToDownsample(
             in_channels,
-            downsample_dw_channels1,
-            downsample_dw_channels2,
+            downsample_dw_channels,
             global_in_channels,
             conv_cfg=self.conv_cfg,
             norm_cfg=self.norm_cfg,
diff --git a/tests/test_models/test_backbone.py b/tests/test_models/test_backbone.py
index 084849aa4..767981bc5 100644
--- a/tests/test_models/test_backbone.py
+++ b/tests/test_models/test_backbone.py
@@ -669,7 +669,7 @@ def test_resnext_backbone():
 def test_fastscnn_backbone():
     with pytest.raises(AssertionError):
         # Fast-SCNN channel constraints.
-        FastSCNN(3, 32, 48, 64, (64, 96, 128), 127, 64, 128)
+        FastSCNN(3, (32, 48), 64, (64, 96, 128), 127, 64, 128)
 
     # Test FastSCNN Standard Forward
     model = FastSCNN()