diff --git a/transport/internet/kcp/xor.go b/transport/internet/kcp/xor.go
index 6de9d295..b9f39f2b 100644
--- a/transport/internet/kcp/xor.go
+++ b/transport/internet/kcp/xor.go
@@ -1,5 +1,3 @@
-// +build !amd64
-
 package kcp
 
 // xorfwd performs XOR forwards in words, x[i] ^= x[i-4], i from 0 to len
diff --git a/transport/internet/kcp/xor_amd64.go b/transport/internet/kcp/xor_amd64.go
deleted file mode 100644
index 40d6a1be..00000000
--- a/transport/internet/kcp/xor_amd64.go
+++ /dev/null
@@ -1,4 +0,0 @@
-package kcp
-
-func xorfwd(x []byte)
-func xorbkd(x []byte)
diff --git a/transport/internet/kcp/xor_amd64.s b/transport/internet/kcp/xor_amd64.s
deleted file mode 100644
index 0c2759d7..00000000
--- a/transport/internet/kcp/xor_amd64.s
+++ /dev/null
@@ -1,47 +0,0 @@
-#include "textflag.h"
-
-// func xorfwd(x []byte)
-TEXT ·xorfwd(SB),NOSPLIT,$0
-  MOVQ x+0(FP), SI  // x[i]
-  MOVQ x_len+8(FP), CX  // x.len
-  MOVQ x+0(FP), DI
-  ADDQ $4, DI       // x[i+4]
-  SUBQ $4, CX
-xorfwdloop:
-  MOVL (SI), AX
-  XORL AX, (DI)
-  ADDQ $4, SI
-  ADDQ $4, DI
-  SUBQ $4, CX
-
-  CMPL CX, $0
-  JE xorfwddone
-
-  JMP xorfwdloop
-xorfwddone:        
-  RET
-
-// func xorbkd(x []byte)
-TEXT ·xorbkd(SB),NOSPLIT,$0
-  MOVQ x+0(FP), SI
-  MOVQ x_len+8(FP), CX  // x.len
-  MOVQ x+0(FP), DI
-  ADDQ CX, SI       // x[-8]
-  SUBQ $8, SI
-  ADDQ CX, DI       // x[-4]
-  SUBQ $4, DI
-  SUBQ $4, CX
-xorbkdloop:
-  MOVL (SI), AX
-  XORL AX, (DI)
-  SUBQ $4, SI
-  SUBQ $4, DI
-  SUBQ $4, CX
-
-  CMPL CX, $0
-  JE xorbkddone
-  
-  JMP xorbkdloop
-
-xorbkddone:        
-  RET