"spurious rep/repne prefix" warning for MPX prefix

Running a small app on win10 I see:

 <spurious rep/repne prefix @0x00eaaec4 (f2 c3): >

0:001> U 0x00eaaec4
buggy!__SEH_prolog4+0x44:
00eaaec4 f2c3            bnd ret

It's part of Intel MPX