diff --git a/system/Debug/Exceptions.php b/system/Debug/Exceptions.php
index de909b6a64..bebe384b26 100644
--- a/system/Debug/Exceptions.php
+++ b/system/Debug/Exceptions.php
@@ -410,7 +410,7 @@ class Exceptions
 			}
 		}
 
-		$out .= str_repeat('</span>', $spans);
+		$out .= str_repeat('</span>', (int)$spans);
 
 		return '<pre><code>'.$out.'</code></pre>';
 	}