diff --git a/python/PyQt6/gui/auto_generated/qgsscalemethodwidget.sip.in b/python/PyQt6/gui/auto_generated/qgsscalemethodwidget.sip.in
index e3bf4c6b742..81507ee30b0 100644
--- a/python/PyQt6/gui/auto_generated/qgsscalemethodwidget.sip.in
+++ b/python/PyQt6/gui/auto_generated/qgsscalemethodwidget.sip.in
@@ -9,6 +9,7 @@
 
 
 
+
 class QgsScaleMethodWidget : QWidget
 {
 %Docstring(signature="appended")
diff --git a/python/gui/auto_generated/qgsscalemethodwidget.sip.in b/python/gui/auto_generated/qgsscalemethodwidget.sip.in
index e3bf4c6b742..81507ee30b0 100644
--- a/python/gui/auto_generated/qgsscalemethodwidget.sip.in
+++ b/python/gui/auto_generated/qgsscalemethodwidget.sip.in
@@ -9,6 +9,7 @@
 
 
 
+
 class QgsScaleMethodWidget : QWidget
 {
 %Docstring(signature="appended")
diff --git a/src/gui/qgsscalemethodwidget.cpp b/src/gui/qgsscalemethodwidget.cpp
index 476025b11ae..f0ee0721984 100644
--- a/src/gui/qgsscalemethodwidget.cpp
+++ b/src/gui/qgsscalemethodwidget.cpp
@@ -16,8 +16,11 @@
  ***************************************************************************/
 
 #include "qgsscalemethodwidget.h"
+#include "qgsapplication.h"
 #include "moc_qgsscalemethodwidget.cpp"
 #include <QHBoxLayout>
+#include <QComboBox>
+#include <QLabel>
 
 QgsScaleMethodWidget::QgsScaleMethodWidget( QWidget *parent )
   : QWidget( parent )
@@ -29,16 +32,36 @@ QgsScaleMethodWidget::QgsScaleMethodWidget( QWidget *parent )
   mCombo->addItem( tr( "Calculate along Top of Map" ), QVariant::fromValue( Qgis::ScaleCalculationMethod::HorizontalTop ) );
   mCombo->addItem( tr( "Calculate along Middle of Map" ), QVariant::fromValue( Qgis::ScaleCalculationMethod::HorizontalMiddle ) );
   mCombo->addItem( tr( "Calculate along Bottom of Map" ), QVariant::fromValue( Qgis::ScaleCalculationMethod::HorizontalBottom ) );
+  mCombo->addItem( tr( "Always Calculate at Equator" ), QVariant::fromValue( Qgis::ScaleCalculationMethod::AtEquator ) );
 
   QHBoxLayout *hLayout = new QHBoxLayout();
   hLayout->setContentsMargins( 0, 0, 0, 0 );
-  hLayout->addWidget( mCombo );
+  hLayout->addWidget( mCombo, 1 );
+
+  // bit of fiddlyness here -- we want the initial spacing to only be visible
+  // when the warning label is shown, so it's embedded inside mWarningLabel
+  // instead of outside it
+  mWarningLabelContainer = new QWidget();
+  QHBoxLayout *warningLayout = new QHBoxLayout();
+  warningLayout->setContentsMargins( 0, 0, 0, 0 );
+  mWarningLabel = new QLabel();
+  const QIcon icon = QgsApplication::getThemeIcon( QStringLiteral( "mIconWarning.svg" ) );
+  const int size = static_cast<int>( std::max( 24.0, mCombo->minimumSize().height() * 0.5 ) );
+  mWarningLabel->setPixmap( icon.pixmap( icon.actualSize( QSize( size, size ) ) ) );
+  const int labelMargin = static_cast<int>( std::round( mCombo->fontMetrics().horizontalAdvance( 'X' ) ) );
+  warningLayout->insertSpacing( 0, labelMargin / 2 );
+  warningLayout->insertWidget( 1, mWarningLabel );
+  mWarningLabelContainer->setLayout( warningLayout );
+  hLayout->addWidget( mWarningLabelContainer );
+  mWarningLabelContainer->hide();
+
   setLayout( hLayout );
 
   setFocusPolicy( Qt::FocusPolicy::StrongFocus );
   setFocusProxy( mCombo );
 
   connect( mCombo, qOverload<int>( &QComboBox::currentIndexChanged ), this, &QgsScaleMethodWidget::methodChanged );
+  connect( mCombo, qOverload<int>( &QComboBox::currentIndexChanged ), this, &QgsScaleMethodWidget::updateWarning );
 }
 
 Qgis::ScaleCalculationMethod QgsScaleMethodWidget::scaleMethod() const
@@ -49,4 +72,30 @@ Qgis::ScaleCalculationMethod QgsScaleMethodWidget::scaleMethod() const
 void QgsScaleMethodWidget::setScaleMethod( Qgis::ScaleCalculationMethod method )
 {
   mCombo->setCurrentIndex( mCombo->findData( QVariant::fromValue( method ) ) );
+  updateWarning();
+}
+
+void QgsScaleMethodWidget::updateWarning()
+{
+  switch ( scaleMethod() )
+  {
+    case Qgis::ScaleCalculationMethod::HorizontalTop:
+    case Qgis::ScaleCalculationMethod::HorizontalMiddle:
+    case Qgis::ScaleCalculationMethod::HorizontalBottom:
+    case Qgis::ScaleCalculationMethod::HorizontalAverage:
+      mWarningLabelContainer->hide();
+      break;
+
+    case Qgis::ScaleCalculationMethod::AtEquator:
+    {
+      mWarningLabelContainer->show();
+      const QString warning = QStringLiteral( "<p>%1</p><p>%2</p>" ).arg( tr( "This method will calculate misleading scales when the map extent is not close to the "
+                                                                              "equator, however it ensures that the scale remains constant and does not "
+                                                                              "change as the map is panned." ),
+                                                                          tr( "This setting is valid for maps in a geographic (latitude/longitude) CRS only." ) );
+      mWarningLabel->setToolTip( warning );
+
+      break;
+    }
+  }
 }
diff --git a/src/gui/qgsscalemethodwidget.h b/src/gui/qgsscalemethodwidget.h
index b50282e251b..a3d672ff210 100644
--- a/src/gui/qgsscalemethodwidget.h
+++ b/src/gui/qgsscalemethodwidget.h
@@ -18,10 +18,12 @@
 #ifndef QGSSCALEMETHODWIDGET_H
 #define QGSSCALEMETHODWIDGET_H
 
-#include <QComboBox>
 #include "qgis_sip.h"
-#include <QPainter> // For QPainter::CompositionMode enum
 #include "qgis_gui.h"
+#include <QWidget>
+
+class QLabel;
+class QComboBox;
 
 /**
  * \ingroup gui
@@ -56,6 +58,11 @@ class GUI_EXPORT QgsScaleMethodWidget : public QWidget
 
   private:
     QComboBox *mCombo = nullptr;
+    QWidget *mWarningLabelContainer = nullptr;
+    QLabel *mWarningLabel = nullptr;
+
+  private slots:
+    void updateWarning();
 };
 
 #endif // QGSSCALEMETHODWIDGET_H