diff --git a/modules/ocl/src/filtering.cpp b/modules/ocl/src/filtering.cpp
index d7502496f9..112205ba73 100644
--- a/modules/ocl/src/filtering.cpp
+++ b/modules/ocl/src/filtering.cpp
@@ -444,8 +444,8 @@ void morphOp(int op, const oclMat &src, oclMat &dst, const Mat &_kernel, Point a
     else if (iterations > 1 && countNonZero(_kernel) == _kernel.rows * _kernel.cols)
     {
         anchor = Point(anchor.x * iterations, anchor.y * iterations);
-        kernel = getStructuringElement(MORPH_RECT, Size(ksize.width + iterations * (ksize.width - 1),
-                                       ksize.height + iterations * (ksize.height - 1)), anchor);
+        kernel = getStructuringElement(MORPH_RECT, Size(ksize.width + (iterations - 1) * (ksize.width - 1),
+                                       ksize.height + (iterations - 1) * (ksize.height - 1)), anchor);
         iterations = 1;
     }
     else