Rectangular instead of square output

It looks rectangular while it should be square ? any idea why?

documentclass[borders=2cm]{standalone}
 usepackage{tikz,pgfplots} 
   pgfplotsset{compat=newest}
begin{document}
  begin{tikzpicture}
begin{axis}[
     xlabel={x},
     ylabel={y},
     axis lines=left,
    axis lines=middle,
    enlargelimits={abs=0.2},
    xmin = 0, xmax = 1.5,
    ymin = -1, ymax = 1.5,
    ytick={1},
    yticklabels={1},
    xtick= {1},
    xticklabels={1},                      
            ]
    draw(0,1)--(1,1)--(1,0);

end{axis}

    end{tikzpicture}
end{document}