diff --git a/interface/lib/classes/simplepie.inc.php b/interface/lib/classes/simplepie.inc.php
index 5d36c09d34b62c7bf2fb1b235099b5344ac6de99..ddba5af4c7babfbb151bd5fdf6b6cfaa3cb482f0 100644
--- a/interface/lib/classes/simplepie.inc.php
+++ b/interface/lib/classes/simplepie.inc.php
@@ -13338,7 +13338,7 @@ class SimplePie_Parse_Date
 			}
 
 			// Convert the number of seconds to an integer, taking decimals into account
-			$second = round($match[6] + $match[7] / pow(10, strlen($match[7])));
+			$second = round($match[6] + $match[7] / pow(10, (int)strlen($match[7])));
 
 			return gmmktime($match[4], $match[5], $second, $match[2], $match[3], $match[1]) - $timezone;
 		}