diff --git a/lib/handlers/db-ops-handler.react.js b/lib/handlers/db-ops-handler.react.js
--- a/lib/handlers/db-ops-handler.react.js
+++ b/lib/handlers/db-ops-handler.react.js
@@ -11,6 +11,8 @@
   peerToPeerMessageTypes,
 } from '../types/tunnelbroker/peer-to-peer-message-types.js';
 import { getConfig } from '../utils/config.js';
+import { getContentSigningKey } from '../utils/crypto-utils.js';
+import { getMessageForException } from '../utils/errors.js';
 import { useDispatch, useSelector } from '../utils/redux-utils.js';
 
 type Props = {
@@ -41,16 +43,26 @@
         type: opsProcessingFinishedActionType,
       });
       if (messageSourceMetadata) {
-        const { messageID, senderDeviceID } = messageSourceMetadata;
-        const message: MessageProcessed = {
-          type: peerToPeerMessageTypes.MESSAGE_PROCESSED,
-          messageID,
-        };
-        await sendMessage({
-          deviceID: senderDeviceID,
-          payload: JSON.stringify(message),
-        });
-        await sqliteAPI.removeInboundP2PMessages([messageID]);
+        try {
+          const { messageID, senderDeviceID } = messageSourceMetadata;
+          const deviceID = await getContentSigningKey();
+          const message: MessageProcessed = {
+            type: peerToPeerMessageTypes.MESSAGE_PROCESSED,
+            messageID,
+            deviceID,
+          };
+          await sendMessage({
+            deviceID: senderDeviceID,
+            payload: JSON.stringify(message),
+          });
+          await sqliteAPI.removeInboundP2PMessages([messageID]);
+        } catch (e) {
+          console.log(
+            `Error while sending confirmation: ${
+              getMessageForException(e) ?? 'unknown error'
+            }`,
+          );
+        }
       }
     })();
   }, [queueFront, dispatch, processDBStoreOperations, sendMessage, sqliteAPI]);
diff --git a/lib/types/tunnelbroker/peer-to-peer-message-types.js b/lib/types/tunnelbroker/peer-to-peer-message-types.js
--- a/lib/types/tunnelbroker/peer-to-peer-message-types.js
+++ b/lib/types/tunnelbroker/peer-to-peer-message-types.js
@@ -91,11 +91,13 @@
 export type MessageProcessed = {
   +type: 'MessageProcessed',
   +messageID: string,
+  +deviceID: string,
 };
 export const messageProcessedValidator: TInterface<MessageProcessed> =
   tShape<MessageProcessed>({
     type: tString(peerToPeerMessageTypes.MESSAGE_PROCESSED),
     messageID: t.String,
+    deviceID: t.String,
   });
 
 export type PeerToPeerMessage =