diff '--color=auto' -ur qtbase-everywhere-src-5.15.19.orig/src/gui/kernel/qguiapplication.cpp qtbase-everywhere-src-5.15.19/src/gui/kernel/qguiapplication.cpp
--- qtbase-everywhere-src-5.15.19.orig/src/gui/kernel/qguiapplication.cpp	2025-11-20 13:50:34.000000000 +0100
+++ qtbase-everywhere-src-5.15.19/src/gui/kernel/qguiapplication.cpp	2026-05-20 17:41:19.345486890 +0200
@@ -263,7 +263,7 @@
 
 static bool checkNeedPortalSupport()
 {
-#if QT_CONFIG(dbus)
+#ifndef QT_NO_DBUS
     return !QStandardPaths::locate(QStandardPaths::RuntimeLocation, QLatin1String("flatpak-info")).isEmpty() || qEnvironmentVariableIsSet("SNAP");
 #else
     return false;
diff '--color=auto' -ur qtbase-everywhere-src-5.15.19.orig/src/platformsupport/services/genericunix/qgenericunixservices.cpp qtbase-everywhere-src-5.15.19/src/platformsupport/services/genericunix/qgenericunixservices.cpp
--- qtbase-everywhere-src-5.15.19.orig/src/platformsupport/services/genericunix/qgenericunixservices.cpp	2025-11-20 13:50:34.000000000 +0100
+++ qtbase-everywhere-src-5.15.19/src/platformsupport/services/genericunix/qgenericunixservices.cpp	2026-05-20 17:41:19.345415350 +0200
@@ -51,7 +51,7 @@
 #include <QtCore/QStandardPaths>
 #include <QtCore/QUrl>
 
-#if QT_CONFIG(dbus)
+#ifndef QT_NO_DBUS
 // These QtCore includes are needed for xdg-desktop-portal support
 #include <QtCore/private/qcore_unix_p.h>
 
@@ -180,7 +180,7 @@
     return ok;
 }
 
-#if QT_CONFIG(dbus)
+#ifndef QT_NO_DBUS
 static inline bool checkNeedPortalSupport()
 {
     return !QStandardPaths::locate(QStandardPaths::RuntimeLocation, QLatin1String("flatpak-info")).isEmpty() || qEnvironmentVariableIsSet("SNAP");
@@ -309,7 +309,7 @@
 bool QGenericUnixServices::openUrl(const QUrl &url)
 {
     if (url.scheme() == QLatin1String("mailto")) {
-#if QT_CONFIG(dbus)
+#ifndef QT_NO_DBUS
         if (checkNeedPortalSupport()) {
             QDBusError error = xdgDesktopPortalSendEmail(url);
             if (isPortalReturnPermanent(error))
@@ -321,7 +321,7 @@
         return openDocument(url);
     }
 
-#if QT_CONFIG(dbus)
+#ifndef QT_NO_DBUS
     if (checkNeedPortalSupport()) {
         QDBusError error = xdgDesktopPortalOpenUrl(url);
         if (isPortalReturnPermanent(error))
@@ -338,7 +338,7 @@
 
 bool QGenericUnixServices::openDocument(const QUrl &url)
 {
-#if QT_CONFIG(dbus)
+#ifndef QT_NO_DBUS
     if (checkNeedPortalSupport()) {
         QDBusError error = xdgDesktopPortalOpenFile(url);
         if (isPortalReturnPermanent(error))