diff --git a/src/DataFormatter/XMLDataFormatter.php b/src/DataFormatter/XMLDataFormatter.php
index c4ba879..db91c34 100644
--- a/src/DataFormatter/XMLDataFormatter.php
+++ b/src/DataFormatter/XMLDataFormatter.php
@@ -117,9 +117,9 @@ public function convertDataObjectWithoutHeader(DataObject $obj, $fields = null,
     {
         $className = $this->sanitiseClassName(get_class($obj));
         $id = $obj->ID;
-        $objHref = Director::absoluteURL($this->config()->api_base . "$className/$obj->ID");
+        $objHref = Director::absoluteURL($this->config()->api_base . "$className/$obj->ID" . ".xml");
 
-        $xml = "<$className href=\"$objHref.xml\">\n";
+        $xml = "<$className href=\"$objHref\">\n";
         foreach ($this->getFieldsForObj($obj) as $fieldName => $fieldType) {
             // Field filtering
             if ($fields && !in_array($fieldName, $fields ?? [])) {
@@ -160,11 +160,11 @@ public function convertDataObjectWithoutHeader(DataObject $obj, $fields = null,
 
                 $fieldName = $relName . 'ID';
                 if ($obj->$fieldName) {
-                    $href = Director::absoluteURL($this->config()->api_base . "$relClass/" . $obj->$fieldName);
+                    $href = Director::absoluteURL($this->config()->api_base . "$relClass/" . $obj->$fieldName . ".xml");
                 } else {
-                    $href = Director::absoluteURL($this->config()->api_base . "$className/$id/$relName");
+                    $href = Director::absoluteURL($this->config()->api_base . "$className/$id/$relName" . ".xml");
                 }
-                $xml .= "<$relName linktype=\"has_one\" href=\"$href.xml\" id=\"" . $obj->$fieldName
+                $xml .= "<$relName linktype=\"has_one\" href=\"$href\" id=\"" . $obj->$fieldName
                     . "\"></$relName>\n";
             }
 
@@ -190,8 +190,8 @@ public function convertDataObjectWithoutHeader(DataObject $obj, $fields = null,
                 $items = $obj->$relName();
                 if ($items) {
                     foreach ($items as $item) {
-                        $href = Director::absoluteURL($this->config()->api_base . "$relClass/$item->ID");
-                        $xml .= "<$relClass href=\"$href.xml\" id=\"{$item->ID}\"></$relClass>\n";
+                        $href = Director::absoluteURL($this->config()->api_base . "$relClass/$item->ID" . ".xml");
+                        $xml .= "<$relClass href=\"$href\" id=\"{$item->ID}\"></$relClass>\n";
                     }
                 }
                 $xml .= "</$relName>\n";
@@ -221,8 +221,8 @@ public function convertDataObjectWithoutHeader(DataObject $obj, $fields = null,
                 $items = $obj->$relName();
                 if ($items) {
                     foreach ($items as $item) {
-                        $href = Director::absoluteURL($this->config()->api_base . "$relClass/$item->ID");
-                        $xml .= "<$relClass href=\"$href.xml\" id=\"{$item->ID}\"></$relClass>\n";
+                        $href = Director::absoluteURL($this->config()->api_base . "$relClass/$item->ID" . ".xml");
+                        $xml .= "<$relClass href=\"$href\" id=\"{$item->ID}\"></$relClass>\n";
                     }
                 }
                 $xml .= "</$relName>\n";
diff --git a/tests/unit/XMLDataFormatterTest.php b/tests/unit/XMLDataFormatterTest.php
index 8da70a1..9b3ffe1 100644
--- a/tests/unit/XMLDataFormatterTest.php
+++ b/tests/unit/XMLDataFormatterTest.php
@@ -5,6 +5,8 @@
 use SilverStripe\Dev\SapphireTest;
 use SilverStripe\RestfulServer\DataFormatter\XMLDataFormatter;
 use Exception;
+use SilverStripe\Control\Controller;
+use SilverStripe\ORM\DataObject;
 
 class XMLDataFormatterTest extends SapphireTest
 {
@@ -74,4 +76,51 @@ public function testConvertStringToArrayMultipleEntitiesException()
         $formatter = new XMLDataFormatter();
         $formatter->convertStringToArray($inputXML);
     }
+
+    /**
+     * Data provider for trailing slash configuration
+     */
+    public function trailingSlashProvider(): array
+    {
+        return [
+            'without trailing slash' => [false],
+            'with trailing slash' => [true],
+        ];
+    }
+
+    /**
+     * Tests wrapper output of {@link XMLDataFormatter::convertDataObjectWithoutHeader()}
+     *
+     * @param bool $addTrailingSlash - Whether to add a trailing slash to the API endpoint
+     * @dataProvider trailingSlashProvider
+     */
+    public function testConvertDataObjectWithoutHeaderClassNameAttribute(bool $addTrailingSlash): void
+    {
+        // Create a mock object
+        $mock = DataObject::create();
+        $mock->ID = 1;
+
+        // Set trailing slash configuration
+        Controller::config()->set('add_trailing_slash', $addTrailingSlash);
+
+        // Create a formatter
+        $formatter = new XMLDataFormatter();
+
+        // Test the output
+        $expectedClass = 'SilverStripe-ORM-DataObject';
+        $expectedHref = sprintf('http://localhost/api/v1/%s/%d.xml', $expectedClass, $mock->ID);
+        $expectedOutput = sprintf(
+            '<%s href="%s"><ID>%d</ID></%s>',
+            $expectedClass,
+            $expectedHref,
+            $mock->ID,
+            $expectedClass
+        );
+
+        $actualOutput = $formatter->convertDataObjectWithoutHeader($mock);
+
+        // remove line breaks and compare
+        $actualOutput = str_replace(["\n", "\r"], '', $actualOutput);
+        $this->assertEquals($expectedOutput, $actualOutput);
+    }
 }