diff --git a/src/quick/framelessquickhelper.cpp b/src/quick/framelessquickhelper.cpp
index b22132e..c0b7ef4 100644
--- a/src/quick/framelessquickhelper.cpp
+++ b/src/quick/framelessquickhelper.cpp
@@ -382,9 +382,7 @@ void FramelessQuickHelperPrivate::setWindowFixedSize(const bool value)
         const QSize size = window->size();
         window->setMinimumSize(size);
         window->setMaximumSize(size);
-        window->setFlags(window->flags() | Qt::MSWindowsFixedSizeDialogHint);
     } else {
-        window->setFlags(window->flags() & ~Qt::MSWindowsFixedSizeDialogHint);
         window->setMinimumSize(kDefaultWindowSize);
         window->setMaximumSize(QSize(QWINDOWSIZE_MAX, QWINDOWSIZE_MAX));
     }
diff --git a/src/widgets/framelesswidgetshelper.cpp b/src/widgets/framelesswidgetshelper.cpp
index 47b54fa..943260a 100644
--- a/src/widgets/framelesswidgetshelper.cpp
+++ b/src/widgets/framelesswidgetshelper.cpp
@@ -119,9 +119,7 @@ void FramelessWidgetsHelperPrivate::setWindowFixedSize(const bool value)
     }
     if (value) {
         window->setFixedSize(window->size());
-        window->setWindowFlags(window->windowFlags() | Qt::MSWindowsFixedSizeDialogHint);
     } else {
-        window->setWindowFlags(window->windowFlags() & ~Qt::MSWindowsFixedSizeDialogHint);
         window->setMinimumSize(kDefaultWindowSize);
         window->setMaximumSize(QSize(QWIDGETSIZE_MAX, QWIDGETSIZE_MAX));
     }