diff --git a/src/calibre/gui2/progress_indicator/QProgressIndicator.cpp b/src/calibre/gui2/progress_indicator/QProgressIndicator.cpp
index 8866078315..6cbf95aa9d 100644
--- a/src/calibre/gui2/progress_indicator/QProgressIndicator.cpp
+++ b/src/calibre/gui2/progress_indicator/QProgressIndicator.cpp
@@ -344,7 +344,7 @@ void CalibreStyle::drawControl(ControlElement element, const QStyleOption *optio
             painter->drawRect(option->rect);
             // draw the dots
             painter->setBrush(option->palette.color(QPalette::ColorGroup::Normal, QPalette::ColorRole::Shadow));
-            bool horizontal = (option->state & QStyle::State_Horizontal) ? true : false;
+            const bool horizontal = (option->state & QStyle::State_Horizontal) ? true : false;
             static const int dot_count = 4;
             const int handle_width = pixelMetric(PM_SplitterWidth, option, widget);
             const int available_diameter = horizontal ? option->rect.width() : option->rect.height();