diff --git a/templates/event-calendar.php b/templates/event-calendar.php
index 04c91af1..acaf53eb 100644
--- a/templates/event-calendar.php
+++ b/templates/event-calendar.php
@@ -183,10 +183,11 @@ if ( $dayswithposts ) {
 	$daywithpost = array();
 }
 
-if (strpos($_SERVER['HTTP_USER_AGENT'], 'MSIE') !== false || stripos($_SERVER['HTTP_USER_AGENT'], 'camino') !== false || stripos($_SERVER['HTTP_USER_AGENT'], 'safari') !== false)
+if ( array_key_exists( 'HTTP_USER_AGENT', $_SERVER ) && preg_match( 'MSIE|camino|safari', $_SERVER[ 'HTTP_USER_AGENT' ] ) ) {
 	$ak_title_separator = "\n";
-else
+} else {
 	$ak_title_separator = ', ';
+}
 
 $ak_titles_for_day = array();
 $ak_post_titles = $wpdb->get_results("SELECT ID, post_title, post_date, DAYOFMONTH(post_date) as dom "