--- coregrind/m_translate.c.orig
+++ coregrind/m_translate.c
@@ -1692,6 +1692,9 @@
    vex_abiinfo.guest_amd64_assume_fs_is_const = True;
    vex_abiinfo.guest_amd64_sigbus_on_misalign = True;
 #  endif
+#  if defined(VGP_amd64_openbsd)
+   vex_abiinfo.guest_amd64_assume_fs_is_const = True;
+#  endif
 #  if defined(VGP_amd64_darwin)
    vex_abiinfo.guest_amd64_assume_gs_is_const = True;
 #  endif
