diff --git a/include/hw/ppc/xics.h b/include/hw/ppc/xics.h
index 2db9f938d3..5aac67ad89 100644
--- a/include/hw/ppc/xics.h
+++ b/include/hw/ppc/xics.h
@@ -149,7 +149,7 @@ struct ICSState {
 
 static inline bool ics_valid_irq(ICSState *ics, uint32_t nr)
 {
-    return (nr >= ics->offset)
+    return (ics->offset != 0) && (nr >= ics->offset)
         && (nr < (ics->offset + ics->nr_irqs));
 }