--- VEX/priv/guest_amd64_helpers.c.orig
+++ VEX/priv/guest_amd64_helpers.c
@@ -3744,6 +3744,13 @@ void LibVEX_GuestAMD64_initialise ( /*OUT*/VexGuestAMD64State* vex_state )
    /* HACK: represent the offset associated with %fs==0. This
       assumes that %fs is only ever zero. */
    vex_state->guest_FS_ZERO = 0;
+#if defined(__OpenBSD__)
+{
+   int fs;
+   __asm__("mov %%fs,%0" : "=r" (fs));
+   vex_state->guest_FS_ZERO = fs;
+}
+#endif
 
    vex_state->guest_RIP = 0;
 
