Index: sys/x86/x86/intr_machdep.c
===================================================================
--- sys/x86/x86/intr_machdep.c
+++ sys/x86/x86/intr_machdep.c
@@ -336,7 +336,7 @@
 	 * XXX: We assume that IRQ 0 is only used for the ISA timer
 	 * device (clk).
 	 */
-	if (vector == 0)
+	if (isrc == interrupt_sources[0])
 		clkintr_pending = 1;
 
 	/*