diff --git a/libao/libao-async.rkt b/libao/libao-async.rkt
index 408c1a3..9d93591 100644
--- a/libao/libao-async.rkt
+++ b/libao/libao-async.rkt
@@ -40,6 +40,7 @@
    [bufsize #:mutable]
    queue-sem
    [queue #:mutable]
+   [stopped #:mutable]
    )
   #:transparent
   )
@@ -63,7 +64,9 @@
                (cond
                  [(eq? command 'stop)
                   (begin
-                    ;(displayln "stopping")
+                    (mutex-lock (ao-shm-mutex shm))
+                    (set-ao-shm-stopped! shm #t)
+                    (mutex-unlock (ao-shm-mutex shm))
                     'done)]
                  [(eq? command 'play)
                   (let ((at-second (cadr elem))
@@ -89,7 +92,7 @@
   )
 
 (define (ao-player ao_device)
-  (let ((shm (make-ao-shm (make-mutex) ao_device 0.0 0 (make-os-semaphore) (make-queue))))
+  (let ((shm (make-ao-shm (make-mutex) ao_device 0.0 0 (make-os-semaphore) (make-queue) #f)))
     (ao-player* shm)
     shm
     )
@@ -103,11 +106,17 @@
   (ao-player ao_device))
 
 (define (ao_stop_async shm)
-  (displayln "Stopping")
   (mutex-lock (ao-shm-mutex shm))
   (enqueue! (ao-shm-queue shm) (list 'stop 0 #f #f))
   (os-semaphore-post (ao-shm-queue-sem shm))
   (mutex-unlock (ao-shm-mutex shm))
+  (let ((stopped (λ ()
+                   (mutex-lock (ao-shm-mutex shm))
+                   (let ((w (ao-shm-stopped shm)))
+                     (mutex-unlock (ao-shm-mutex shm))
+                     w))))
+    (while (eq? (stopped) #f))
+         (sleep 0.01))
   )
 
 (define (ao_play_async shm at-second buf-size buf)