diff --git a/core/textdocumentgenerator.cpp b/core/textdocumentgenerator.cpp
index 25b3937b9..8dbc5a75b 100644
--- a/core/textdocumentgenerator.cpp
+++ b/core/textdocumentgenerator.cpp
@@ -42,6 +42,11 @@ TextDocumentConverter::~TextDocumentConverter()
     delete d;
 }
 
+DocumentViewport TextDocumentConverter::calculateViewport( QTextDocument *document, const QTextBlock &block )
+{
+    return Utils::calculateViewport( document, block );
+}
+
 /**
  * Generic Generator Implementation
  */
diff --git a/core/textdocumentgenerator.h b/core/textdocumentgenerator.h
index 299d018b1..fc6d91854 100644
--- a/core/textdocumentgenerator.h
+++ b/core/textdocumentgenerator.h
@@ -72,7 +72,7 @@ class OKULAR_EXPORT TextDocumentConverter : public QObject
          * Note: This method should be called at the end of the convertion, because it
          *       triggers QTextDocument to do the layout calculation.
          */
-        DocumentViewport calculateViewport( const QTextBlock &block );
+        DocumentViewport calculateViewport( QTextDocument *document, const QTextBlock &block );
 
     private:
         class Private;