Ending sentences in an aligned equation

Question

This is more of a general "mathematical english/punctuation" question, but I figure TeX users will know the answer. The following sentence seems natural:

We define the $xyz$ constant via $xyz=\int_0^\infty f(y)dy$.

Note the period at the end, which is of course correct. What if I decide to align the equation for $xyz$?

We define the $xyz$ constant via 

\begin{align}
    xyz=\int_0^\infty f(y)dy 
\end{align}  

Should I still place a period at the end of this sentence (in the aligned equation)? Is it considered bad form to end sentences in the middle of aligned equations like this?

Thanks!