diff --git a/src/kdbusservice.cpp b/src/kdbusservice.cpp
--- a/src/kdbusservice.cpp
+++ b/src/kdbusservice.cpp
@@ -94,8 +94,18 @@
         objectPath.replace(QLatin1Char('-'), QLatin1Char('_')); // see spec change at https://bugs.freedesktop.org/show_bug.cgi?id=95129
 
         if (options & Multiple) {
-            const QString pid = QString::number(QCoreApplication::applicationPid());
-            d->serviceName += QLatin1Char('-') + pid;
+            bool inSandbox = false;
+            if (!qEnvironmentVariableIsEmpty("XDG_RUNTIME_DIR")) {
+                const QByteArray runtimeDir = qgetenv("XDG_RUNTIME_DIR");
+                if (!runtimeDir.isEmpty()) {
+                    inSandbox = QFileInfo::exists(QString::fromUtf8(runtimeDir) + QLatin1String("/flatpak-info"));
+                }
+            }
+
+            if (inSandbox)
+                d->serviceName += QStringLiteral(".kdbus-") + QDBusConnection::sessionBus().baseService().replace(QRegularExpression(QStringLiteral("[\\.:]")), QStringLiteral("_"));
+            else
+                d->serviceName += QLatin1Char('-') + QString::number(QCoreApplication::applicationPid());
         }
 
         QDBusConnection::sessionBus().registerObject(QStringLiteral("/MainApplication"), QCoreApplication::instance(),