diff --git a/src/gui/qgsfieldexpressionwidget.cpp b/src/gui/qgsfieldexpressionwidget.cpp
index 17046b87e769..2bbb3b67ea7c 100644
--- a/src/gui/qgsfieldexpressionwidget.cpp
+++ b/src/gui/qgsfieldexpressionwidget.cpp
@@ -392,7 +392,8 @@ void QgsFieldExpressionWidget::updateLineEditStyle( const QString &expression )
       currentField( &isExpression, &isValid );
     }
     QFont font = mCombo->lineEdit()->font();
-    font.setItalic( isExpression );
+    font.setFamily( ( QgsCodeEditor::getMonospaceFont() ).family() );
+    font.setItalic( false );
     mCombo->lineEdit()->setFont( font );
 
     if ( isExpression && !isValid )