diff --git a/src/plugins/diffeditor/diffeditorwidget.cpp b/src/plugins/diffeditor/diffeditorwidget.cpp
index 346fc69c85d..7dc7be70f9c 100644
--- a/src/plugins/diffeditor/diffeditorwidget.cpp
+++ b/src/plugins/diffeditor/diffeditorwidget.cpp
@@ -718,6 +718,8 @@ void DiffEditorWidget::showDiff()
     const int leftHorizontalValue = m_leftEditor->horizontalScrollBar()->value();
     const int rightHorizontalValue = m_rightEditor->horizontalScrollBar()->value();
 
+    m_leftEditor->setBlockSelection(false);
+    m_rightEditor->setBlockSelection(false);
     m_leftEditor->clear();
     m_rightEditor->clear();
     m_leftEditor->clearLineNumbers();