diff --git a/src/impl/results_notifier.cpp b/src/impl/results_notifier.cpp
index 55300f56..b097cec0 100644
--- a/src/impl/results_notifier.cpp
+++ b/src/impl/results_notifier.cpp
@@ -40,17 +40,6 @@ void ResultsNotifier::release_data() noexcept
     m_query = nullptr;
 }
 
-static bool map_moves(size_t& idx, CollectionChangeIndices const& changes)
-{
-    for (auto&& move : changes.moves) {
-        if (move.from == idx) {
-            idx = move.to;
-            return true;
-        }
-    }
-    return false;
-}
-
 // Most of the inter-thread synchronization for run(), prepare_handover(),
 // attach_to(), detach(), release_data() and deliver() is done by
 // RealmCoordinator external to this code, which has some potentially
@@ -117,14 +106,18 @@ void ResultsNotifier::run()
             next_rows.push_back(m_tv[i].get_index());
 
         if (changes) {
+            auto move_map = changes->moves;
+            std::sort(begin(move_map), end(move_map),
+                      [](auto const& a, auto const& b) { return a.from < b.from; });
             for (auto& idx : m_previous_rows) {
-                if (!map_moves(idx, *changes)) {
-                    if (changes->deletions.contains(idx))
-                        idx = npos;
-                    else {
-                        REALM_ASSERT_DEBUG(!changes->insertions.contains(idx));
-                    }
-                }
+                auto it = lower_bound(begin(move_map), end(move_map), idx,
+                                      [](auto const& a, auto b) { return a.from < b; });
+                if (it != move_map.end() && it->from == idx)
+                    idx = it->to;
+                else if (changes->deletions.contains(idx))
+                    idx = npos;
+                else
+                    REALM_ASSERT_DEBUG(!changes->insertions.contains(idx));
             }
         }