diff --git a/util/rcu.c b/util/rcu.c
index bd73b8eb47..27802a4bed 100644
--- a/util/rcu.c
+++ b/util/rcu.c
@@ -283,7 +283,7 @@ void rcu_unregister_thread(void)
     qemu_mutex_unlock(&rcu_gp_lock);
 }
 
-static void __attribute__((__constructor__)) rcu_init(void)
+static void rcu_init_complete(void)
 {
     QemuThread thread;
 
@@ -291,8 +291,39 @@ static void __attribute__((__constructor__)) rcu_init(void)
     qemu_event_init(&rcu_gp_event, true);
 
     qemu_event_init(&rcu_call_ready_event, false);
+
+    /* The caller is assumed to have iothread lock, so the call_rcu thread
+     * must have been quiescent even after forking, just recreate it.
+     */
     qemu_thread_create(&thread, "call_rcu", call_rcu_thread,
                        NULL, QEMU_THREAD_DETACHED);
 
     rcu_register_thread();
 }
+
+#ifdef CONFIG_POSIX
+static void rcu_init_lock(void)
+{
+    qemu_mutex_lock(&rcu_gp_lock);
+}
+
+static void rcu_init_unlock(void)
+{
+    qemu_mutex_unlock(&rcu_gp_lock);
+}
+
+static void rcu_init_child(void)
+{
+    qemu_mutex_unlock(&rcu_gp_lock);
+    memset(&registry, 0, sizeof(registry));
+    rcu_init_complete();
+}
+#endif
+
+static void __attribute__((__constructor__)) rcu_init(void)
+{
+#ifdef CONFIG_POSIX
+    pthread_atfork(rcu_init_lock, rcu_init_unlock, rcu_init_child);
+#endif
+    rcu_init_complete();
+}