diff --git a/actions/peoplesearch.php b/actions/peoplesearch.php
index 323065d7a9..f700cf46e7 100644
--- a/actions/peoplesearch.php
+++ b/actions/peoplesearch.php
@@ -115,7 +115,8 @@ class PeoplesearchAction extends SearchAction {
 	}
 
 	function highlight($text, $terms) {
-		$pattern = '/('.implode('|',array_map('htmlspecialchars', $terms)).')/i';
+		$terms = array_map('preg_quote', array_map('htmlspecialchars', $terms));
+		$pattern = '/('.implode('|',$terms).')/i';
 		$result = preg_replace($pattern, '<strong>\\1</strong>', htmlspecialchars($text));
 		return $result;
 	}