diff --git a/ch2/ch2-mandelbrot/src/main.rs b/ch2/ch2-mandelbrot/src/main.rs
index a887cef0..5af363ee 100644
--- a/ch2/ch2-mandelbrot/src/main.rs
+++ b/ch2/ch2-mandelbrot/src/main.rs
@@ -11,10 +11,10 @@ fn calculate_mandelbrot(      // <2>
   height: usize,              // <5>
   ) -> Vec<Vec<usize>> {
 
-  let mut rows: Vec<_> = Vec::with_capacity(width); // <6>
+  let mut rows: Vec<_> = Vec::with_capacity(height); // <6>
   for img_y in 0..height {                          // <7>
 
-    let mut row: Vec<usize> = Vec::with_capacity(height);
+    let mut row: Vec<usize> = Vec::with_capacity(width);
     for img_x in 0..width {
 
       let x_percent = (img_x as f64 / width as f64);
@@ -70,7 +70,7 @@ fn render_mandelbrot(escape_vals: Vec<Vec<usize>>) {
 }
 
 fn main() {
-  
+
   let mandelbrot = calculate_mandelbrot(1000, -2.0, 1.0, -1.0,
                                         1.0, 100, 24);