diff --git a/drivers/lguest/page_tables.c b/drivers/lguest/page_tables.c
index 699187ab380099a32d926a83dde84d96e7124e85..5b9ac32801c7604b25c64804fb888aa1ebbbceab 100644
--- a/drivers/lguest/page_tables.c
+++ b/drivers/lguest/page_tables.c
@@ -1002,6 +1002,7 @@ void guest_set_pgd(struct lguest *lg, unsigned long gpgdir, u32 idx)
 			kill_guest(&lg->cpus[0],
 				   "Cannot populate switcher mapping");
 		}
+		lg->pgdirs[pgdir].last_host_cpu = -1;
 	}
 }