diff --git a/modules/flann/include/opencv2/flann/autotuned_index.h b/modules/flann/include/opencv2/flann/autotuned_index.h
index 0670d19e2b..6ffb9297c4 100644
--- a/modules/flann/include/opencv2/flann/autotuned_index.h
+++ b/modules/flann/include/opencv2/flann/autotuned_index.h
@@ -377,6 +377,7 @@ private:
         // evaluate kdtree for all parameter combinations
         for (size_t i = 0; i < FLANN_ARRAY_LEN(testTrees); ++i) {
             CostData cost;
+            cost.params["algorithm"] = FLANN_INDEX_KDTREE;
             cost.params["trees"] = testTrees[i];
 
             evaluate_kdtree(cost);