diff --git a/server_conn.go b/server_conn.go
index dfe6f70..41151c1 100644
--- a/server_conn.go
+++ b/server_conn.go
@@ -13,8 +13,6 @@ import (
 	"github.com/sagernet/sing/common/rw"
 )
 
-var _ N.HandshakeConn = (*serverConn)(nil)
-
 type serverConn struct {
 	N.ExtendedConn
 	responseWritten bool
@@ -77,11 +75,6 @@ func (c *serverConn) Upstream() any {
 	return c.ExtendedConn
 }
 
-var (
-	_ N.HandshakeConn = (*serverPacketConn)(nil)
-	_ N.PacketConn    = (*serverPacketConn)(nil)
-)
-
 type serverPacketConn struct {
 	N.ExtendedConn
 	access          sync.Mutex
@@ -183,11 +176,6 @@ func (c *serverPacketConn) FrontHeadroom() int {
 	return 2
 }
 
-var (
-	_ N.HandshakeConn = (*serverPacketAddrConn)(nil)
-	_ N.PacketConn    = (*serverPacketAddrConn)(nil)
-)
-
 type serverPacketAddrConn struct {
 	N.ExtendedConn
 	access          sync.Mutex