diff --git a/arch/x86/lguest/boot.c b/arch/x86/lguest/boot.c
index 4e22fa0..a5d8e1a 100644
--- a/arch/x86/lguest/boot.c
+++ b/arch/x86/lguest/boot.c
@@ -586,6 +586,9 @@
 
 	for (i = 0; i < LGUEST_IRQS; i++) {
 		int vector = FIRST_EXTERNAL_VECTOR + i;
+		/* Some systems map "vectors" to interrupts weirdly.  Lguest has
+		 * a straightforward 1 to 1 mapping, so force that here. */
+		__get_cpu_var(vector_irq)[vector] = i;
 		if (vector != SYSCALL_VECTOR) {
 			set_intr_gate(vector, interrupt[vector]);
 			set_irq_chip_and_handler_name(i, &lguest_irq_controller,