diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
index e58342ace11f2dd10ad09d81930ba76f6eab90d4..79f22b018c6b8e097ebf60770c9c71fd630de9ea 100644
--- a/kernel/irq/internals.h
+++ b/kernel/irq/internals.h
@@ -12,7 +12,7 @@
 #include <linux/sched/clock.h>
 
 #ifdef CONFIG_SPARSE_IRQ
-# define IRQ_BITMAP_BITS	(NR_IRQS + 8196)
+# define IRQ_BITMAP_BITS	(1 << 19)
 #else
 # define IRQ_BITMAP_BITS	NR_IRQS
 #endif