diff --git a/system/Format/FormatterInterface.php b/system/Format/FormatterInterface.php
index 0c2492b90a77..5f6d6df3870a 100644
--- a/system/Format/FormatterInterface.php
+++ b/system/Format/FormatterInterface.php
@@ -21,7 +21,7 @@ interface FormatterInterface
     /**
      * Takes the given data and formats it.
      *
-     * @param array<array-key, mixed>|object|string $data
+     * @param mixed $data
      *
      * @return false|non-empty-string
      */
diff --git a/system/Format/JSONFormatter.php b/system/Format/JSONFormatter.php
index ac237fcc7af3..fb882a0e4eac 100644
--- a/system/Format/JSONFormatter.php
+++ b/system/Format/JSONFormatter.php
@@ -26,7 +26,7 @@ class JSONFormatter implements FormatterInterface
     /**
      * Takes the given data and formats it.
      *
-     * @param array<array-key, mixed>|object|string $data
+     * @param mixed $data
      *
      * @return false|non-empty-string
      */
diff --git a/system/Format/XMLFormatter.php b/system/Format/XMLFormatter.php
index efef70cec2cb..0f058e8a7ff7 100644
--- a/system/Format/XMLFormatter.php
+++ b/system/Format/XMLFormatter.php
@@ -27,7 +27,7 @@ class XMLFormatter implements FormatterInterface
     /**
      * Takes the given data and formats it.
      *
-     * @param array<array-key, mixed>|object|string $data
+     * @param mixed $data
      *
      * @return false|non-empty-string
      */
diff --git a/system/HTTP/ResponseInterface.php b/system/HTTP/ResponseInterface.php
index 258cbcf3c452..a1fbcb4acc06 100644
--- a/system/HTTP/ResponseInterface.php
+++ b/system/HTTP/ResponseInterface.php
@@ -200,7 +200,7 @@ public function setContentType(string $mime, string $charset = 'UTF-8');
     /**
      * Converts the $body into JSON and sets the Content Type header.
      *
-     * @param array<array-key, mixed>|object|string $body
+     * @param mixed $body
      *
      * @return $this
      */
@@ -218,7 +218,7 @@ public function getJSON();
     /**
      * Converts $body into XML, and sets the correct Content-Type.
      *
-     * @param array<array-key, mixed>|string $body
+     * @param mixed $body
      *
      * @return $this
      */
diff --git a/system/HTTP/ResponseTrait.php b/system/HTTP/ResponseTrait.php
index 95e58b01a05d..50a8ab8c319e 100644
--- a/system/HTTP/ResponseTrait.php
+++ b/system/HTTP/ResponseTrait.php
@@ -169,7 +169,7 @@ public function setContentType(string $mime, string $charset = 'UTF-8')
     /**
      * Converts the $body into JSON and sets the Content Type header.
      *
-     * @param array<array-key, mixed>|object|string $body
+     * @param mixed $body
      *
      * @return $this
      */
@@ -201,7 +201,7 @@ public function getJSON()
     /**
      * Converts $body into XML, and sets the correct Content-Type.
      *
-     * @param array<array-key, mixed>|string $body
+     * @param mixed $body
      *
      * @return $this
      */
@@ -234,8 +234,8 @@ public function getXML()
      * Handles conversion of the data into the appropriate format,
      * and sets the correct Content-Type header for our response.
      *
-     * @param array<array-key, mixed>|object|string $body
-     * @param string                                $format Valid: json, xml
+     * @param mixed  $body
+     * @param string $format Valid: json, xml
      *
      * @return false|string
      *
diff --git a/tests/system/Test/TestResponseTest.php b/tests/system/Test/TestResponseTest.php
index 2ec981e786e5..c79104e43e72 100644
--- a/tests/system/Test/TestResponseTest.php
+++ b/tests/system/Test/TestResponseTest.php
@@ -314,7 +314,7 @@ public function testGetJSONEmptyJSON(): void
     public function testGetJSONFalseJSON(): void
     {
         $this->getTestResponse('<h1>Hello World</h1>');
-        $this->response->setJSON(false, true); // @phpstan-ignore argument.type (Needed for testing)
+        $this->response->setJSON(false, true);
 
         // this should be FALSE - json_encode(false)
         $this->assertSame('false', $this->testResponse->getJSON());
@@ -323,7 +323,7 @@ public function testGetJSONFalseJSON(): void
     public function testGetJSONTrueJSON(): void
     {
         $this->getTestResponse('<h1>Hello World</h1>');
-        $this->response->setJSON(true, true); // @phpstan-ignore argument.type (Needed for testing)
+        $this->response->setJSON(true, true);
 
         // this should be TRUE - json_encode(true)
         $this->assertSame('true', $this->testResponse->getJSON());
diff --git a/user_guide_src/source/changelogs/v4.7.5.rst b/user_guide_src/source/changelogs/v4.7.5.rst
index b5f11bc83f79..787d67e7de9a 100644
--- a/user_guide_src/source/changelogs/v4.7.5.rst
+++ b/user_guide_src/source/changelogs/v4.7.5.rst
@@ -22,6 +22,8 @@ Message Changes
 Changes
 *******
 
+- **Response:** ``setJSON()`` and ``setXML()``, and the ``FormatterInterface::format()`` contract implemented by ``JSONFormatter`` and ``XMLFormatter``, now type their body/data parameter as ``mixed`` instead of ``array|object|string``, matching what they already accepted at runtime (e.g., scalars and ``bool``).
+
 ************
 Deprecations
 ************