diff --git a/lib/test_cpumask.c b/lib/test_cpumask.c
index 4ebf9f5805f32..4d353614d853e 100644
--- a/lib/test_cpumask.c
+++ b/lib/test_cpumask.c
@@ -73,7 +73,7 @@ static void test_cpumask_first(struct kunit *test)
 static void test_cpumask_last(struct kunit *test)
 {
 	KUNIT_EXPECT_LE(test, nr_cpumask_bits, cpumask_last(&mask_empty));
-	KUNIT_EXPECT_EQ(test, nr_cpumask_bits - 1, cpumask_last(cpu_possible_mask));
+	KUNIT_EXPECT_EQ(test, nr_cpu_ids - 1, cpumask_last(cpu_possible_mask));
 }
 
 static void test_cpumask_next(struct kunit *test)