diff --git a/modules/video/include/opencv2/video/background_segm.hpp b/modules/video/include/opencv2/video/background_segm.hpp
index b8785cc7c..791ea1ad6 100644
--- a/modules/video/include/opencv2/video/background_segm.hpp
+++ b/modules/video/include/opencv2/video/background_segm.hpp
@@ -241,7 +241,7 @@ private:
     double minVal_;
 
     cv::Size frameSize_;
-    size_t frameNum_;
+    int frameNum_;
 
     cv::Mat_<int> nfeatures_;
     cv::Mat_<int> colors_;