diff --git a/ostd/src/arch/x86/trap/syscall.S b/ostd/src/arch/x86/trap/syscall.S
index 7aefb36b..51eb8720 100644
--- a/ostd/src/arch/x86/trap/syscall.S
+++ b/ostd/src/arch/x86/trap/syscall.S
@@ -15,6 +15,8 @@
  * SPDX-License-Identifier: MPL-2.0
  */
 
+.code64
+
 .text
     # extern "sysv64" fn syscall_return(&mut GeneralRegs)
 .global syscall_return
diff --git a/ostd/src/arch/x86/trap/trap.S b/ostd/src/arch/x86/trap/trap.S
index 19cbfe85..7ab5ede4 100644
--- a/ostd/src/arch/x86/trap/trap.S
+++ b/ostd/src/arch/x86/trap/trap.S
@@ -15,6 +15,8 @@
  * SPDX-License-Identifier: MPL-2.0
  */
 
+.code64
+
 .equ NUM_INT, 256
 
 .altmacro