diff --git a/MdePkg/Library/BaseLib/X64/Thunk16.S b/MdePkg/Library/BaseLib/X64/Thunk16.S
index 51798dc224..84cafa19ac 100644
--- a/MdePkg/Library/BaseLib/X64/Thunk16.S
+++ b/MdePkg/Library/BaseLib/X64/Thunk16.S
@@ -262,7 +262,7 @@ ASM_PFX(InternalAsmThunk16):
     movl    %edx,%eax                   # eax <- transition code address
     andl    $0xf,%edx
     shll    $12,%eax                    # segment address in high order 16 bits
-    lea     (_BackFromUserCode - ASM_PFX(m16Start))(%rdx), %ax
+    lea     (ASM_PFX(BackFromUserCode) - ASM_PFX(m16Start))(%rdx), %ax
     stosl                               # [edi] <- return address of user code
     sgdt    0x60(%rsp)                  # save GDT stack in argument space
     movzwq  0x60(%rsp), %r10            # r10 <- GDT limit