diff --git a/tools/attack/adv-accept/src/main.rs b/tools/attack/adv-accept/src/main.rs
index a8b8d1bad..a8456298c 100644
--- a/tools/attack/adv-accept/src/main.rs
+++ b/tools/attack/adv-accept/src/main.rs
@@ -411,8 +411,13 @@ mod gap {
             }
             let sl = &mut addrs[lane * loads..(lane + 1) * loads];
             sl.sort_unstable();
-            sl.dedup();
-            *lane_distinct += sl.len() as u64;
+            let mut distinct = 0u64;
+            for k in 0..loads {
+                if k == 0 || sl[k] != sl[k - 1] {
+                    distinct += 1;
+                }
+            }
+            *lane_distinct += distinct;
         }
         hashes
     }