diff --git a/arch/x64/entry.S b/arch/x64/entry.S
index 3150f1ce68975329df0195f461225ad5c773f98f..f8b81500bd4a56697be176c0fdc4c89991a38bd3 100644
--- a/arch/x64/entry.S
+++ b/arch/x64/entry.S
@@ -106,7 +106,7 @@ stack_trampoline:  # %rsi=arg, %rdi=func, %rdx=stack
 	.cfi_startproc simple
 	.cfi_def_cfa %rsp, 0
 	# align the stack at 16 bytes for sse
-	andq $-15, %rdx
+	andq $-16, %rdx
 	sub $8, %rdx
 	mov %rsp, -8(%rdx)
 	lea -8(%rdx), %rsp