diff --git a/tests/dbus-helpers/dbus_rauc_server.cpp b/tests/dbus-helpers/dbus_rauc_server.cpp
index 230a5d6..94930c3 100644
--- a/tests/dbus-helpers/dbus_rauc_server.cpp
+++ b/tests/dbus-helpers/dbus_rauc_server.cpp
@@ -76,6 +76,9 @@
         std::lock_guard<std::mutex> lock(m_mtx);
         if (!m_operationInProgress) {
             m_operationInProgress = true;
+
+            if (m_installThread.joinable())
+                m_installThread.join();
             m_installThread = std::thread(&DBusRAUCServer::installBundle, this);
         } else {
             throw sdbus::Error("org.gtk.GDBus.UnmappedGError.Quark._g_2dio_2derror_2dquark.Code30", "Already processing a different method");