diff --git a/qt/main.cpp b/qt/main.cpp
--- a/qt/main.cpp
+++ b/qt/main.cpp
@@ -37,7 +37,9 @@
 #include <QPushButton>
 #include <QString>
 #include <QWidget>
+#if QT_VERSION >= 0x050000
 #include <QWindow>
+#endif
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -132,6 +134,7 @@
 static void
 setup_foreground_window(QWidget *widget, WId parentWid)
 {
+#if QT_VERSION >= 0x050000
     /* For windows set the desktop window as the transient parent */
     QWindow *parentWindow = nullptr;
     if (parentWid) {
@@ -154,6 +157,7 @@
             wndHandle->setTransientParent(parentWindow);
         }
     }
+#endif
     widget->setWindowFlags(Qt::Window |
                            Qt::CustomizeWindowHint |
                            Qt::WindowTitleHint |
diff --git a/qt/pinentrydialog.cpp b/qt/pinentrydialog.cpp
--- a/qt/pinentrydialog.cpp
+++ b/qt/pinentrydialog.cpp
@@ -225,9 +225,7 @@
             this, SLOT(focusChanged(QWidget *, QWidget *)));
 
     setWindowState(Qt::WindowMinimized);
-    QTimer::singleShot(0, this, [this] () {
-        raiseWindow (this);
-    });
+    QTimer::singleShot(0, this, SLOT(raiseWindow));
 }
 
 void PinEntryDialog::showEvent(QShowEvent *event)