diff --git a/drivers/lguest/x86/core.c b/drivers/lguest/x86/core.c
index a6b717644be0d50efc2f257e52e9e543cc545833..d6d7ac0982ab6e7a3d15874fe5d88d6c465a1523 100644
--- a/drivers/lguest/x86/core.c
+++ b/drivers/lguest/x86/core.c
@@ -324,6 +324,11 @@ static void rewrite_hypercall(struct lg_cpu *cpu)
 	u8 insn[3] = {0xcd, 0x1f, 0x90};
 
 	__lgwrite(cpu, guest_pa(cpu, cpu->regs->eip), insn, sizeof(insn));
+	/* The above write might have caused a copy of that page to be made
+	 * (if it was read-only).  We need to make sure the Guest has
+	 * up-to-date pagetables.  As this doesn't happen often, we can just
+	 * drop them all. */
+	guest_pagetable_clear_all(cpu);
 }
 
 static bool is_hypercall(struct lg_cpu *cpu)