diff --git a/modules/flann/include/opencv2/flann/autotuned_index.h b/modules/flann/include/opencv2/flann/autotuned_index.h
index 6ffb9297c4..30f8b92a81 100644
--- a/modules/flann/include/opencv2/flann/autotuned_index.h
+++ b/modules/flann/include/opencv2/flann/autotuned_index.h
@@ -30,6 +30,8 @@
 #ifndef OPENCV_FLANN_AUTOTUNED_INDEX_H_
 #define OPENCV_FLANN_AUTOTUNED_INDEX_H_
 
+#include <sstream>
+
 #include "general.h"
 #include "nn_index.h"
 #include "ground_truth.h"