inorganic chemistry - Confusion with Law of Equivalence

Law of equivalence states that

One equivalent of an element combines with one equivalent of the other.

Equivalent of $\ce{Na}$ is $22.99$ and that of $\ce{O}$ is $8$. By the law of equivalence, $1$ equivalent of $\ce{Na}$ combines with $1$ equivalent of $\ce{O}$. But in $\ce{Na2O2}$,

$$23 \times 2 ~\text{parts by weight of sodium combines with } 16 \times 2~\text{parts by weight of oxygen} \\\implies 23~\text{parts by weight of sodium combines with } 16~\text{parts by weight of oxygen}$$ which means one equivalent of sodium combines with two equivalents of oxygen which is contradiction to law of equivalence. So why does this compound not follow the law of equivalence?