diff --git a/include/FramelessHelper/Core/framelesshelpercore_global.h b/include/FramelessHelper/Core/framelesshelpercore_global.h
index fcfa598d..c3e3d666 100644
--- a/include/FramelessHelper/Core/framelesshelpercore_global.h
+++ b/include/FramelessHelper/Core/framelesshelpercore_global.h
@@ -100,6 +100,13 @@ QT_END_NAMESPACE
    using QT_ENTER_EVENT_TYPE = QEvent;
 #endif
 
+// QLatin1StringView can't be constexpr until Qt6?
+#if (QT_VERSION >= QT_VERSION_CHECK(6, 0, 0))
+#  define Q_STRING_CONSTEXPR constexpr
+#else
+#  define Q_STRING_CONSTEXPR
+#endif
+
 #ifndef QUtf8String
 #  define QUtf8String(str) QString::fromUtf8(str)
 #endif
@@ -167,7 +174,7 @@ QT_END_NAMESPACE
 
 #ifndef FRAMELESSHELPER_STRING_CONSTANT2
 #  define FRAMELESSHELPER_STRING_CONSTANT2(name, str) \
-     [[maybe_unused]] static constexpr const auto k##name = FRAMELESSHELPER_STRING(str);
+     [[maybe_unused]] static Q_STRING_CONSTEXPR const auto k##name = FRAMELESSHELPER_STRING(str);
 #endif
 
 #ifndef FRAMELESSHELPER_BYTEARRAY_CONSTANT
diff --git a/src/core/framelesshelper_win.cpp b/src/core/framelesshelper_win.cpp
index 71ed3414..0e488cc1 100644
--- a/src/core/framelesshelper_win.cpp
+++ b/src/core/framelesshelper_win.cpp
@@ -648,7 +648,7 @@ bool FramelessHelperWin::nativeEventFilter(const QByteArray &eventType, void *me
     const LPARAM lParam = msg->lParam;
 
 #if (QT_VERSION < QT_VERSION_CHECK(6, 5, 1))
-    const auto updateRestoreGeometry = [windowId, &data](const bool ignoreWindowState) -> void {
+    const auto updateRestoreGeometry = [windowId, &muData](const bool ignoreWindowState) -> void {
         if (!ignoreWindowState && !Utils::isWindowNoState(windowId)) {
             return;
         }