PHP preg_replace：匹配包含短划线的单词

I am facing a problem searching words in a string and converting them into links. How to make a search that considers words containing a "-" as whole word and not as 2 words separated by "-" ?

Here is an example, if I search for the word "exhaustive", my search function will also match the part of the word "non-exhaustive", although i don't want this word to be matched.

$string = "Bla bla bla non-exhaustive blabla bla exhaustive";
$words = array('exhaustive','non-exhaustive');
foreach ($words as $word) {
    $string = preg_replace('/\b'.$word.'\b/i', '<a href=#>'.$word.'</a>',$string);
}

echo $string;

Result :

Bla bla bla non-exhaustive blabla bla exhaustive

Thank you very much for your help !

$string = preg_replace('/\b[^\-]' . preg_quote($word) . '\b/i', '<a href=#>' . $word . '</a>',$string);

Should do the trick :)

*edit, Aleks did beat me with just 2 sec :p