2 files changed, 7 insertions, 0 deletions
diff --git a/src/widgets/kernel/qapplication.cpp b/src/widgets/kernel/qapplication.cpp
index af3d134a5a..a8d13c64ee 100644
--- a/src/widgets/kernel/qapplication.cpp
+++ b/src/widgets/kernel/qapplication.cpp
@@ -1073,7 +1073,10 @@ void QApplication::setStyle(QStyle *style)
     if (QApplicationPrivate::set_pal) {
         QApplication::setPalette(*QApplicationPrivate::set_pal);
     } else if (QApplicationPrivate::sys_pal) {
+        clearSystemPalette();
+        initSystemPalette();
         QApplicationPrivate::initializeWidgetPaletteHash();
+        QApplicationPrivate::initializeWidgetFontHash();
         QApplicationPrivate::setPalette_helper(*QApplicationPrivate::sys_pal, /*className=*/0, /*clearWidgetPaletteHash=*/false);
     } else if (!QApplicationPrivate::sys_pal) {
         // Initialize the sys_pal if it hasn't happened yet...
diff --git a/src/widgets/kernel/qapplication_qpa.cpp b/src/widgets/kernel/qapplication_qpa.cpp
index b947f1b497..1f8e950d00 100644
--- a/src/widgets/kernel/qapplication_qpa.cpp
+++ b/src/widgets/kernel/qapplication_qpa.cpp
@@ -275,6 +275,8 @@ void QApplicationPrivate::initializeWidgetPaletteHash()
     QPlatformTheme *platformTheme = QGuiApplicationPrivate::platformTheme();
     if (!platformTheme)
         return;
+    qt_app_palettes_hash()->clear();
+
     setPossiblePalette(platformTheme->palette(QPlatformTheme::ToolButtonPalette), "QToolButton");
     setPossiblePalette(platformTheme->palette(QPlatformTheme::ButtonPalette), "QAbstractButton");
     setPossiblePalette(platformTheme->palette(QPlatformTheme::CheckBoxPalette), "QCheckBox");
@@ -298,6 +300,8 @@ void QApplicationPrivate::initializeWidgetFontHash()
     if (!theme)
         return;
     FontHash *fontHash = qt_app_fonts_hash();
+    fontHash->clear();
+
     if (const QFont *font = theme->font(QPlatformTheme::MenuFont))
         fontHash->insert(QByteArrayLiteral("QMenu"), *font);
     if (const QFont *font = theme->font(QPlatformTheme::MenuBarFont))