How can I align an imagesc subplot with a line subplot?

I am trying to align an image with a graph of the vertical sum of the image (a kind of image profile). But I cannot get the line plot's width to align with the imagesc of the plot above it. This is what I've tried:

A = randn(40);

sumA = sum(A)

h1 = subplot(211);
p1 = get(h1, 'pos');

imagesc(A), axis equal, axis off

h2 = subplot(212);
p2 = get(h2, 'pos');
p2(3) = p1(3);
set(h2, 'pos', p2);
plot(sumA)

The output is as shown in the image attached:

As you can see, the graph is much wider than the matrix shown by imagesc.