diff --git a/drivers/lguest/x86/core.c b/drivers/lguest/x86/core.c
index fb2b7ef7868e..b4eb675a807e 100644
--- a/drivers/lguest/x86/core.c
+++ b/drivers/lguest/x86/core.c
@@ -287,6 +287,18 @@ static int emulate_insn(struct lg_cpu *cpu)
 	/* Decoding x86 instructions is icky. */
 	insn = lgread(cpu, physaddr, u8);
 
+	/*
+	 * Around 2.6.33, the kernel started using an emulation for the
+	 * cmpxchg8b instruction in early boot on many configurations.  This
+	 * code isn't paravirtualized, and it tries to disable interrupts.
+	 * Ignore it, which will Mostly Work.
+	 */
+	if (insn == 0xfa) {
+		/* "cli", or Clear Interrupt Enable instruction.  Skip it. */
+		cpu->regs->eip++;
+		return 1;
+	}
+
 	/*
 	 * 0x66 is an "operand prefix".  It means it's using the upper 16 bits
 	 * of the eax register.