diff --git a/modules/flann/include/opencv2/flann/autotuned_index.h b/modules/flann/include/opencv2/flann/autotuned_index.h
index d90f739aff..0b02f5670a 100644
--- a/modules/flann/include/opencv2/flann/autotuned_index.h
+++ b/modules/flann/include/opencv2/flann/autotuned_index.h
@@ -54,7 +54,7 @@ NNIndex<Distance>* create_index_by_type(const Matrix<typename Distance::ElementT
 
 struct AutotunedIndexParams : public IndexParams
 {
-    AutotunedIndexParams(float target_precision = 0.8, float build_weight = 0.01, float memory_weight = 0, float sample_fraction = 0.1)
+    AutotunedIndexParams(float target_precision = 0.8f, float build_weight = 0.01f, float memory_weight = 0.f, float sample_fraction = 0.1f)
     {
         (*this)["algorithm"] = FLANN_INDEX_AUTOTUNED;
         // precision desired (used for autotuning, -1 otherwise)
diff --git a/modules/flann/include/opencv2/flann/composite_index.h b/modules/flann/include/opencv2/flann/composite_index.h
index 37a6223f88..5affd81749 100644
--- a/modules/flann/include/opencv2/flann/composite_index.h
+++ b/modules/flann/include/opencv2/flann/composite_index.h
@@ -46,7 +46,7 @@ namespace cvflann
 struct CompositeIndexParams : public IndexParams
 {
     CompositeIndexParams(int trees = 4, int branching = 32, int iterations = 11,
-                         flann_centers_init_t centers_init = FLANN_CENTERS_RANDOM, float cb_index = 0.2 )
+                         flann_centers_init_t centers_init = FLANN_CENTERS_RANDOM, float cb_index = 0.2f )
     {
         (*this)["algorithm"] = FLANN_INDEX_KMEANS;
         // number of randomized trees to use (for kdtree)
diff --git a/modules/flann/include/opencv2/flann/kmeans_index.h b/modules/flann/include/opencv2/flann/kmeans_index.h
index fd7fe2bd39..7ced99ca81 100644
--- a/modules/flann/include/opencv2/flann/kmeans_index.h
+++ b/modules/flann/include/opencv2/flann/kmeans_index.h
@@ -62,7 +62,7 @@ struct KMeansIndexParams : public IndexParams
 {
     KMeansIndexParams(int branching = 32, int iterations = 11,
                       flann_centers_init_t centers_init = FLANN_CENTERS_RANDOM,
-                      float cb_index = 0.2, int trees = 1 )
+                      float cb_index = 0.2f, int trees = 1 )
     {
         (*this)["algorithm"] = FLANN_INDEX_KMEANS;
         // branching factor