Chi-square pivot for an exponential rate

Let $X_{1},X_{2},…,X_{n}$ be a random sample from $\operatorname{Exp}(\theta)$ distribution, where $\theta\in(0,\infty)$. If $\bar{X}=\frac{1}{n}\sum_{i=1}^{n}X_{i}$, then a $95\%$ confidence interval for $\theta$ is