diff --git a/src/Util/Temporal.php b/src/Util/Temporal.php
index 0ce59bfaf0..d3ed346908 100644
--- a/src/Util/Temporal.php
+++ b/src/Util/Temporal.php
@@ -359,6 +359,8 @@ class Temporal
 				return sprintf($format, $r, (($r == 1) ? $str[0] : $str[1]));
 			}
 		}
+
+		return '';
 	}
 
 	/**