diff --git a/src/stub/src/amd64-linux.elf-fold.S b/src/stub/src/amd64-linux.elf-fold.S
index cd3da36f..ebab5fc7 100644
--- a/src/stub/src/amd64-linux.elf-fold.S
+++ b/src/stub/src/amd64-linux.elf-fold.S
@@ -201,11 +201,16 @@ p_memsz= 5*NBPW
 
         mov %ebx,%edi  # fd
         call close
+
+.macro NOTRACK
+       .byte 0x3e
+.endm
+
 no_pse_map:
         pop %arg1  # ADRU: unfolded upx_main2 etc.
         pop %arg2  # LENU
         push $__NR_munmap; pop %rax
-        /*notrack*/ jmp *(%r14)  # goto: syscall; pop %rdx; ret
+        NOTRACK; jmp *(%r14)  # goto: syscall; pop %rdx; ret
 
 get_page_mask: .globl get_page_mask
         mov PAGE_MASK(%rip),%rax
diff --git a/src/stub/src/i386-linux.elf-fold.S b/src/stub/src/i386-linux.elf-fold.S
index c3dfb03f..d52f7ed0 100644
--- a/src/stub/src/i386-linux.elf-fold.S
+++ b/src/stub/src/i386-linux.elf-fold.S
@@ -285,8 +285,11 @@ L60:
         push eax
         push eax  // 32 bytes of zeroes now on stack, ready for 'popa'
 
+.macro NOTRACK
+        .byte 0x3e
+.endm
         mov al, __NR_munmap  // eax was 0 from L60
-        /*notrack*/ jmp [edi]  // unmap ourselves via escape hatch, then goto entry
+        NOTRACK; jmp [edi]  // unmap ourselves via escape hatch, then goto entry
 
         section SYSCALLS
 // Sometimes linux enforces page-aligned address