Index: api/ApiFormatXml.php
===================================================================
--- api/ApiFormatXml.php	(revision 59374)
+++ api/ApiFormatXml.php	(working copy)
@@ -173,7 +173,7 @@
 			$this->setWarning( 'Stylesheet should have .xsl extension.' );
 			return;
 		}
-		$this->printText( '<?xml-stylesheet href="' . $nt->escapeLocalURL( 'action=raw' ) . '" type="text/xml" ?>' );
+		$this->printText( '<?xml-stylesheet href="' . $nt->escapeLocalURL( 'action=raw&ctype=application/xml' ) . '" type="text/xsl" ?>' );
 	}
 	
 	public function getAllowedParams() {
Index: RawPage.php
===================================================================
--- RawPage.php	(revision 59374)
+++ RawPage.php	(working copy)
@@ -26,6 +26,9 @@
 		$allowedCTypes = array('text/x-wiki', $wgJsMimeType, 'text/css', 'application/x-zope-edit');
 		$this->mArticle =& $article;
 		$this->mTitle =& $article->mTitle;
+		if ($article->mTitle->getNamespace() == NS_MEDIAWIKI) {
+			$allowedCTypes[] = 'application/xml';
+		}
 
 		if( $request === false ) {
 			$this->mRequest =& $wgRequest;