diff --git a/DOCS/man/en/vo.rst b/DOCS/man/en/vo.rst
index 1e8518b23e..251e71ce03 100644
--- a/DOCS/man/en/vo.rst
+++ b/DOCS/man/en/vo.rst
@@ -344,7 +344,7 @@ opengl
 
     dither-size-fruit=<2-8>
         Set the size of the dither matrix (default: 6). The actual size of
-        the matrix is ``(N^2) x (N^2)`` for an option value of ``N``, so a
+        the matrix is ``(2^N) x (2^N)`` for an option value of ``N``, so a
         value of 6 gives a size of 64x64. The matrix is generated at startup
         time, and a large matrix can take rather long to compute (seconds).