diff --git a/scheme/console.scm b/scheme/console.scm
index e9d8d1e..c80dc19 100644
--- a/scheme/console.scm
+++ b/scheme/console.scm
@@ -77,8 +77,9 @@
    (lambda ()
      (sync
       (wrap (result-buffer-other-object-has-focus-rv)
-	    (lambda (ignore)
-	      (pause-console-output console)))))))
+	    (lambda (ack-channel)
+	      (pause-console-output console)
+	      (send ack-channel 'ignore)))))))
 
 (define (make-console-viewer console buffer)
   (lambda (message)
diff --git a/scheme/win.scm b/scheme/win.scm
index 247d472..7957842 100644
--- a/scheme/win.scm
+++ b/scheme/win.scm
@@ -133,8 +133,10 @@
   (make-channel))
 
 (define (signal-result-buffer-object-change)
-  (debug-message "signal-result-buffer-object-change")
-  (send result-buffer-changed-channel 'ignore))
+  (let ((ack-channel (make-channel)))
+    (debug-message "signal-result-buffer-object-change")
+    (send result-buffer-changed-channel ack-channel)
+    (receive ack-channel)))
 
 (define (spawn-result-buffer-surveillant)
   (spawn
@@ -144,11 +146,14 @@
 	(wrap (receive-rv result-buffer-changes-subscribers)
 	      (lambda (answer-channel)
 		(debug-message "result-buffer-surveillant 1")
-		(receive result-buffer-changed-channel)
-		(send answer-channel 'ignore)
+		(sync (wrap
+		       (receive-rv result-buffer-changed-channel)
+		       (lambda (ack-channel)
+			 (send answer-channel ack-channel))))
 		(lp)))
 	(wrap (receive-rv result-buffer-changed-channel)
-	      (lambda (ignore)
+	      (lambda (ack-channel)
+		(send ack-channel 'no-one-is-interested)
 		(debug-message "result-buffer-surveillant 2")
 		(lp))))))))