diff --git a/guacamole-common-js/src/main/resources/guacamole.js b/guacamole-common-js/src/main/resources/guacamole.js
index 9652d12ba..9c549f896 100644
--- a/guacamole-common-js/src/main/resources/guacamole.js
+++ b/guacamole-common-js/src/main/resources/guacamole.js
@@ -944,6 +944,9 @@ Guacamole.Client = function(tunnel) {
                 channel.play(mimetype, duration, stream.getBlob());
             };
 
+            // Send success response
+            tunnel.sendMessage("ack", stream_index, "OK", 0x0000);
+
         },
 
         "blob": function(parameters) {
@@ -964,6 +967,9 @@ Guacamole.Client = function(tunnel) {
             // Write data
             stream.receive(arrayBuffer);
 
+            // Send success response
+            tunnel.sendMessage("ack", stream_index, "OK", 0x0000);
+
         },
 
         "cfill": function(parameters) {
@@ -1175,6 +1181,9 @@ Guacamole.Client = function(tunnel) {
             if (guac_client.onfile)
                 guac_client.onfile(filename, stream);
 
+            // Send success response
+            tunnel.sendMessage("ack", stream_index, "OK", 0x0000);
+
         },
 
         "identity": function(parameters) {
@@ -1526,6 +1535,9 @@ Guacamole.Client = function(tunnel) {
 
             };
 
+            // Send success response
+            tunnel.sendMessage("ack", stream_index, "OK", 0x0000);
+
         }