diff --git a/src/Illuminate/Support/Str.php b/src/Illuminate/Support/Str.php
index 0b53e4fc280..66d6a6c7afe 100644
--- a/src/Illuminate/Support/Str.php
+++ b/src/Illuminate/Support/Str.php
@@ -482,7 +482,7 @@ public static function pan($value)
     {
         $value = (string) $value;
 
-        return join(' ', str_split($value, 4));
+        return implode(' ', str_split($value, 4));
     }
 
     /**