Is $z^{3/2}$ analytic? If so why can't I use Cauchy-Goursat Theorem?

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$$\oint_\Gamma z^{3/2} dz, \quad \text{where } \Gamma : |z| = 1$$

It should meet the requirements of the Theorem of Cauchy-Goursat so it should be $0$. But when I do it:

$$ \oint_0^{2\pi}e^{3i\theta/2} ie^{i\theta}d\theta = \oint_0^{2\pi}ie^{5i\theta/2}d\theta = -4/5$$

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Please tell us what is your definition of $z^{3/2}$ so that it's a continuous function on that path of integration?

You might as well just ask your question with $z^{1/2}$ too: the square root function is more basic and exhibits the same issue.