diff --git a/p521/src/arithmetic/field.rs b/p521/src/arithmetic/field.rs
index 0f91ad4fc..3957c08b3 100644
--- a/p521/src/arithmetic/field.rs
+++ b/p521/src/arithmetic/field.rs
@@ -188,9 +188,7 @@ impl FieldElement {
         let mut i = 0;
         while i < (BYTES / 2) {
             let j = BYTES - i - 1;
-            let tmp = ret[i];
-            ret[i] = ret[j];
-            ret[j] = tmp;
+            ret.swap(i, j);
             i += 1;
         }