diff --git a/src/gui/qgsrichtexteditor.cpp b/src/gui/qgsrichtexteditor.cpp
index d8775783886f..a2b7115d3ad0 100644
--- a/src/gui/qgsrichtexteditor.cpp
+++ b/src/gui/qgsrichtexteditor.cpp
@@ -752,16 +752,21 @@ void QgsRichTextEditor::setText( const QString &text )
 {
   if ( text.isEmpty() )
   {
-    setPlainText( text );
+    mTextEdit->setPlainText( text );
+    mSourceEdit->clear();
     return;
   }
-  if ( text[0] == '<' )
+
+  const thread_local QRegularExpression sIsHtmlRx( QStringLiteral( "^\\s*<" ) );
+  if ( sIsHtmlRx.match( text ).hasMatch() )
   {
-    setHtml( text );
+    mTextEdit->setHtml( text );
+    mSourceEdit->setText( text );
   }
   else
   {
-    setPlainText( text );
+    mTextEdit->setPlainText( text );
+    mSourceEdit->setText( text );
   }
 }
 
diff --git a/src/gui/qgsrichtexteditor.h b/src/gui/qgsrichtexteditor.h
index c83551ddeda1..37968593d737 100644
--- a/src/gui/qgsrichtexteditor.h
+++ b/src/gui/qgsrichtexteditor.h
@@ -162,8 +162,6 @@ class GUI_EXPORT QgsRichTextEditor : public QWidget, protected Ui::QgsRichTextEd
     void focusInEvent( QFocusEvent *event ) override;
 
   private slots:
-    void setPlainText( const QString &text ) { mTextEdit->setPlainText( text ); }
-    void setHtml( const QString &text ) { mTextEdit->setHtml( text ); }
     void textRemoveFormat();
     void textRemoveAllFormat();
     void textBold();