diff --git a/htdocs/core/class/CMailFile.class.php b/htdocs/core/class/CMailFile.class.php
index ef8d07dfb45..b3027b90885 100644
--- a/htdocs/core/class/CMailFile.class.php
+++ b/htdocs/core/class/CMailFile.class.php
@@ -1350,10 +1350,10 @@ class CMailFile
 		// Build the list of image extensions
 		$extensions = array_keys($this->image_types);
 
-
+		$matches = array();
 		preg_match_all('/(?:"|\')([^"\']+\.('.implode('|', $extensions).'))(?:"|\')/Ui', $this->html, $matches);  // If "xxx.ext" or 'xxx.ext' found
 
-		if ($matches)
+		if (! empty($matches))
 		{
 			$i=0;
 			foreach ($matches[1] as $full)