diff --git a/tests/editorwatchdog.js b/tests/editorwatchdog.js
index 499439a..c1124ed 100644
--- a/tests/editorwatchdog.js
+++ b/tests/editorwatchdog.js
@@ -937,7 +937,7 @@ describe( 'EditorWatchdog', () => {
 				constructor( sourceElements, config ) {
 					super( config );
 
-					this.data.processor = new HtmlDataProcessor();
+					this.data.processor = new HtmlDataProcessor( this.editing.view.document );
 
 					// Create a root for each source element.
 					for ( const rootName of Object.keys( sourceElements ) ) {