diff --git a/libao/libao.rkt b/libao/libao.rkt
index b5bb368..d7cd10a 100644
--- a/libao/libao.rkt
+++ b/libao/libao.rkt
@@ -156,11 +156,16 @@
 
     (if (number? handle)
         (let ((ao-device (hash-ref devices handle #f)))
-          (close-device #f ao-device))
+          (unless (eq? ao-device #f)
+            (displayln (format "Closing ao device ~a" ao-device))
+            (close-device #f ao-device)
+            (hash-remove! devices handle)))
         (let ((handle-num (ao-handle-handle-num handle)))
           (let ((ao-device (hash-ref devices handle-num #f)))
-            (displayln (format "ao-device = ~a" ao-device))
-            (close-device handle ao-device))
+            (unless (eq? ao-device #f)
+              (displayln (format "ao-device = ~a" ao-device))
+              (close-device handle ao-device)
+              (hash-remove! devices handle-num)))
           )
         )
   )