diff --git a/mandelbrot.c b/mandelbrot.c
index 688a59cb803027828a6f89d31a2f98cba632cb53..7f80424f115873b78ff558a379c11668024e7a59 100644
--- a/mandelbrot.c
+++ b/mandelbrot.c
@@ -16,8 +16,8 @@ int main()
 {
          /* screen ( integer) coordinate */
        int iX,iY;
-       const int iXmax = 200;
-       const int iYmax = 200;
+       const int iXmax = 800;
+       const int iYmax = 800;
        /* world ( double) coordinate = parameter plane*/
        double Cx,Cy;
        const double CxMin=-2.5;