diff --git a/lib/tunnelbroker/tunnelbroker-context.js b/lib/tunnelbroker/tunnelbroker-context.js
--- a/lib/tunnelbroker/tunnelbroker-context.js
+++ b/lib/tunnelbroker/tunnelbroker-context.js
@@ -50,7 +50,10 @@
 type Promises = { [clientMessageID: string]: PromiseCallbacks };
 
 type TunnelbrokerContextType = {
-  +sendMessage: (message: TunnelbrokerClientMessageToDevice) => Promise<void>,
+  +sendMessage: (
+    message: TunnelbrokerClientMessageToDevice,
+    messageID: ?string,
+  ) => Promise<void>,
   +addListener: (listener: TunnelbrokerSocketListener) => void,
   +removeListener: (listener: TunnelbrokerSocketListener) => void,
   +connected: boolean,
@@ -383,9 +386,10 @@
 
   const sendMessage: (
     message: TunnelbrokerClientMessageToDevice,
+    messageID: ?string,
   ) => Promise<void> = React.useCallback(
-    (message: TunnelbrokerClientMessageToDevice) => {
-      const clientMessageID = uuid.v4();
+    (message: TunnelbrokerClientMessageToDevice, messageID: ?string) => {
+      const clientMessageID = messageID ?? uuid.v4();
       const messageToDevice: MessageToDeviceRequest = {
         type: tunnelbrokerMessageTypes.MESSAGE_TO_DEVICE_REQUEST,
         clientMessageID,