diff --git a/rust/src/fileio_prefs.rs b/rust/src/fileio_prefs.rs
index 6d6b63e97..7e24e5805 100644
--- a/rust/src/fileio_prefs.rs
+++ b/rust/src/fileio_prefs.rs
@@ -2631,9 +2631,8 @@ mod tests {
         let callback = size_of::<Option<FIO_listMultipleFilesDisplayFn>>();
         let projection_alignment = align_of::<FIO_listFileInfoProjection_t>();
         let projection_payload = 2 * size_of::<u64>() + 4 * size_of::<c_int>() + size_of::<u32>();
-        let projection_size = (projection_payload + projection_alignment - 1)
-            / projection_alignment
-            * projection_alignment;
+        let projection_size =
+            projection_payload.div_ceil(projection_alignment) * projection_alignment;
 
         assert_eq!(
             align_of::<FIO_listFileInfoProjection_t>(),