diff --git a/src/ParameterProvider.php b/src/ParameterProvider.php
index 2c4722c..ad5b7d3 100644
--- a/src/ParameterProvider.php
+++ b/src/ParameterProvider.php
@@ -62,7 +62,7 @@ public function getEscapedUploadPageText() {
 	}
 
 	/**
-	 * @param string $key
+	 * @param int $key
 	 * @return string
 	 */
 	private function getEscapedParameter( $key ) {
diff --git a/src/SimpleBatchUpload.php b/src/SimpleBatchUpload.php
index 62a59b7..fa0b7a9 100644
--- a/src/SimpleBatchUpload.php
+++ b/src/SimpleBatchUpload.php
@@ -61,10 +61,12 @@ public function getConfiguration() {
 
 	/**
 	 * @param \Parser $parser
+	 *
 	 * @return bool
+	 * @throws \MWException
 	 */
 	public function registerParserFunction( &$parser ) {
-		$parser->setFunctionHook( 'batchupload', [ new UploadButtonRenderer( $parser->getOutput() ), 'renderParserFunction' ], SFH_OBJECT_ARGS );
+		$parser->setFunctionHook( 'batchupload', [ new UploadButtonRenderer(), 'renderParserFunction' ], SFH_OBJECT_ARGS );
 		return true;
 	}
 
diff --git a/src/SpecialBatchUpload.php b/src/SpecialBatchUpload.php
index 50283fc..5a9e451 100644
--- a/src/SpecialBatchUpload.php
+++ b/src/SpecialBatchUpload.php
@@ -69,7 +69,7 @@ public function execute( $subpage ) {
 	 * @param string|null $subpage
 	 */
 	private function addPageContentToOutput( $subpage ) {
-		$renderer = new UploadButtonRenderer( $this->getOutput() );
+		$renderer = new UploadButtonRenderer();
 		$renderer->renderSpecialPage( $this, $subpage );
 	}
 
diff --git a/src/UploadButtonRenderer.php b/src/UploadButtonRenderer.php
index 8a6c540..a0a890e 100644
--- a/src/UploadButtonRenderer.php
+++ b/src/UploadButtonRenderer.php
@@ -23,6 +23,8 @@
  */
 
 namespace SimpleBatchUpload;
+use Parser;
+use PPFrame;
 
 
 /**
@@ -31,15 +33,13 @@
  */
 class UploadButtonRenderer {
 
-	private $output;
-
 	/**
-	 * @param \Parser $parser
-	 * @param \PPFrame $frame
+	 * @param Parser $parser
+	 * @param PPFrame $frame
 	 * @param $args
 	 * @return array
 	 */
-	public function renderParserFunction( \Parser $parser, \PPFrame $frame, $args ) {
+	public function renderParserFunction( Parser $parser, PPFrame $frame, $args ) {
 
 		$args = array_map( [ $frame, 'expand' ], $args );
 		$output = $parser->getOutput();