diff --git a/acpid/src/acpi.rs b/acpid/src/acpi.rs
index 33811e50c4..9bd620ef6d 100644
--- a/acpid/src/acpi.rs
+++ b/acpid/src/acpi.rs
@@ -191,7 +191,7 @@ impl Sdt {
 
         while left > 0 {
             let to_copy = std::cmp::min(left, length_per_iteration);
-            let additional_pages = PhysmapGuard::map(offset, length_per_iteration.div_ceil(PAGE_SIZE))?;
+            let additional_pages = PhysmapGuard::map(offset, to_copy.div_ceil(PAGE_SIZE))?;
 
             loaded.extend(&additional_pages[..to_copy]);