Let $\mathscr{X}$ be a normal separated $k$-scheme of finite type. Let $D$ be a reduced effective divisor on $\mathscr{X}$ such that the pair $(\mathscr{X},D)$ is dlt and the divisor $K_{\mathscr{X}}+D$ is Cartier. Assume also that all the prime components of $D$ are $\mathbb{Q}$-Cartier. Let $C$ be a one-dimensional stratum of $D$. Then, on an open neighbourhood of $C$, the scheme $\mathscr{X}$ is regular and $D$ is a divisor with strict normal crossings.