diff --git a/system/Format/JSONFormatter.php b/system/Format/JSONFormatter.php
index 7933351a0507..b4a80822e8be 100644
--- a/system/Format/JSONFormatter.php
+++ b/system/Format/JSONFormatter.php
@@ -22,7 +22,7 @@ class JSONFormatter implements FormatterInterface
     /**
      * Takes the given data and formats it.
      *
-     * @param mixed $data
+     * @param array|bool|float|int|object|string|null $data
      *
      * @return false|string (JSON string | false)
      */
diff --git a/system/Format/XMLFormatter.php b/system/Format/XMLFormatter.php
index 2a18e388a576..322ac32d2abd 100644
--- a/system/Format/XMLFormatter.php
+++ b/system/Format/XMLFormatter.php
@@ -23,7 +23,7 @@ class XMLFormatter implements FormatterInterface
     /**
      * Takes the given data and formats it.
      *
-     * @param mixed $data
+     * @param array|bool|float|int|object|string|null $data
      *
      * @return false|string (XML string | false)
      */