diff --git a/src/plugins/diffeditor/sidebysidediffeditorwidget.h b/src/plugins/diffeditor/sidebysidediffeditorwidget.h
index 1750a13ba8e..5fbd253e7c3 100644
--- a/src/plugins/diffeditor/sidebysidediffeditorwidget.h
+++ b/src/plugins/diffeditor/sidebysidediffeditorwidget.h
@@ -40,7 +40,6 @@ class TextEditorWidget;
 QT_BEGIN_NAMESPACE
 class QMenu;
 class QSplitter;
-class QTextBlock;
 QT_END_NAMESPACE
 
 namespace DiffEditor {