diff --git a/kstyle/breezestyle.cpp b/kstyle/breezestyle.cpp
--- a/kstyle/breezestyle.cpp
+++ b/kstyle/breezestyle.cpp
@@ -5038,7 +5038,12 @@
 
         //try to understand if anywhere the widget is under mouse, not just the handle, use _animations in case of QWidget, option->styleObject in case of QML
         #if QT_VERSION >= 0x050000
-        const bool widgetMouseOver( widget ? _animations->scrollBarEngine().isHovered( widget, QStyle::SC_ScrollBarGroove )  : option->styleObject->property("hover").toBool());
+        bool widgetMouseOver = false;
+        if (widget) {
+            widgetMouseOver = _animations->scrollBarEngine().isHovered(widget, QStyle::SC_ScrollBarGroove);
+        } else if (option->styleObject) {
+            widgetMouseOver = option->styleObject->property("hover").toBool();
+        }
         #else
         const bool widgetMouseOver( _animations->scrollBarEngine().isHovered( widget, QStyle::SC_ScrollBarGroove ) );
         #endif