diff --git a/kernel/irq/matrix.c b/kernel/irq/matrix.c
index 5092494bf26140dbc367472dbe00841790b95f51..28e74a8c790b228ee95944a8d3e5acf933b97d5d 100644
--- a/kernel/irq/matrix.c
+++ b/kernel/irq/matrix.c
@@ -8,7 +8,7 @@
 #include <linux/cpu.h>
 #include <linux/irq.h>
 
-#define IRQ_MATRIX_SIZE	(BITS_TO_LONGS(IRQ_MATRIX_BITS) * sizeof(unsigned long))
+#define IRQ_MATRIX_SIZE	(BITS_TO_LONGS(IRQ_MATRIX_BITS))
 
 struct cpumap {
 	unsigned int		available;