diff --git a/kernel/bounds.c b/kernel/bounds.c
index b529182e8b04..c5a9fcd2d622 100644
--- a/kernel/bounds.c
+++ b/kernel/bounds.c
@@ -19,7 +19,7 @@ int main(void)
 	DEFINE(NR_PAGEFLAGS, __NR_PAGEFLAGS);
 	DEFINE(MAX_NR_ZONES, __MAX_NR_ZONES);
 #ifdef CONFIG_SMP
-	DEFINE(NR_CPUS_BITS, ilog2(CONFIG_NR_CPUS));
+	DEFINE(NR_CPUS_BITS, bits_per(CONFIG_NR_CPUS));
 #endif
 	DEFINE(SPINLOCK_SIZE, sizeof(spinlock_t));
 #ifdef CONFIG_LRU_GEN