diff --git a/qemu-thread-win32.c b/qemu-thread-win32.c
index db8e744..ff80e84 100644
--- a/qemu-thread-win32.c
+++ b/qemu-thread-win32.c
@@ -243,10 +243,12 @@
 
 void qemu_thread_create(QemuThread *thread,
                        void *(*start_routine)(void *),
-                       void *arg)
+                       void *arg, int mode)
 {
     HANDLE hThread;
 
+    assert(mode == QEMU_THREAD_DETACHED);
+
     struct QemuThreadData *data;
     qemu_thread_init();
     data = g_malloc(sizeof *data);