diff --git a/lib/test_bitmap.c b/lib/test_bitmap.c
index 61ed71c1daba..6b13150667f5 100644
--- a/lib/test_bitmap.c
+++ b/lib/test_bitmap.c
@@ -278,6 +278,8 @@ static void __init test_replace(void)
 	unsigned int nlongs = DIV_ROUND_UP(nbits, BITS_PER_LONG);
 	DECLARE_BITMAP(bmap, 1024);
 
+	BUILD_BUG_ON(EXP2_IN_BITS < nbits * 2);
+
 	bitmap_zero(bmap, 1024);
 	bitmap_replace(bmap, &exp2[0 * nlongs], &exp2[1 * nlongs], exp2_to_exp3_mask, nbits);
 	expect_eq_bitmap(bmap, exp3_0_1, nbits);