diff --git a/modules/alphamat/include/opencv2/alphamat.hpp b/modules/alphamat/include/opencv2/alphamat.hpp
index 003b305e5e6..26222b9cbea 100644
--- a/modules/alphamat/include/opencv2/alphamat.hpp
+++ b/modules/alphamat/include/opencv2/alphamat.hpp
@@ -7,6 +7,8 @@
 #ifndef _OPENCV_ALPHAMAT_HPP_
 #define _OPENCV_ALPHAMAT_HPP_
 
+#include <opencv2/core.hpp>
+
 /**
  * @defgroup alphamat Alpha Matting
  * Alpha matting is used to extract a foreground object with soft boundaries from a background image.