# Align* inside enumerate goes out of margin

I am writing my thesis and have a lot of align* environments inside an enumerate environment. I have to use align* environment as I have huge math equations which are split over multiple lines. However often the text goes out of the margins without even showing a warning. Why is this happening and how to avoid it? Here is an example

\documentclass[draft]{report}
\usepackage{amsmath}
\usepackage{showframe}

\begin{document}

\begin{enumerate}
\item  No warning
\begin{align*}
blahblahblahblahblahblahblahblahblablahblahblahblahblahblahblablahblahblah
\end{align*}
\item But we see warning here
\begin{align*}
blahblahblahblahblahblahblahblahblablahblahblahblahblahblahblablahblahblahblah
\end{align*}
\end{enumerate}

and also here
\begin{align*}
blahblahblahblahblahblahblahblahblablahblahblahblahblahblahblablahblahblahbl
\end{align*}

\end{document}


Overfull \hbox (20.35115pt too wide) detected at line 11