diff --git a/library/core/src/slice/sort.rs b/library/core/src/slice/sort.rs
index 2181f9a811855..8f02a44667085 100644
--- a/library/core/src/slice/sort.rs
+++ b/library/core/src/slice/sort.rs
@@ -198,8 +198,11 @@ where
             }
 
             // Choose the greater child.
-            if child + 1 < v.len() && is_less(&v[child], &v[child + 1]) {
-                child += 1;
+            if child + 1 < v.len() {
+                // We need a branch to be sure not to out-of-bounds index,
+                // but it's highly predictable.  The comparison, however,
+                // is better done branchless, especially for primitives.
+                child += is_less(&v[child], &v[child + 1]) as usize;
             }
 
             // Stop if the invariant holds at `node`.