diff --git a/mmseg/models/decode_heads/sep_fcn_head.py b/mmseg/models/decode_heads/sep_fcn_head.py
index b7a9bae2f..21d108aba 100644
--- a/mmseg/models/decode_heads/sep_fcn_head.py
+++ b/mmseg/models/decode_heads/sep_fcn_head.py
@@ -37,8 +37,8 @@ class DepthwiseSeparableFCNHead(FCNHead):
             self.convs[i] = DepthwiseSeparableConvModule(
                 self.channels,
                 self.channels,
-                kernel_size=3,
-                padding=1,
+                kernel_size=self.kernel_size,
+                padding=self.kernel_size//2,
                 norm_cfg=self.norm_cfg)
 
         if self.concat_input: