diff --git a/keyserver/src/socket/tunnelbroker.js b/keyserver/src/socket/tunnelbroker.js
--- a/keyserver/src/socket/tunnelbroker.js
+++ b/keyserver/src/socket/tunnelbroker.js
@@ -53,9 +53,9 @@
       const message: TBKeyserverConnectionInitializationMessage = {
         type: 'sessionRequest',
         accessToken,
-        deviceId: deviceID,
+        deviceID,
         deviceType: 'keyserver',
-        userId: userID,
+        userID,
       };
 
       tunnelbrokerSocket.send(JSON.stringify(message));
diff --git a/lib/types/tunnelbroker-messages.js b/lib/types/tunnelbroker-messages.js
--- a/lib/types/tunnelbroker-messages.js
+++ b/lib/types/tunnelbroker-messages.js
@@ -6,10 +6,10 @@
 
 type TBSharedConnectionInitializationMessage = {
   +type: 'sessionRequest',
-  +deviceId: string,
+  +deviceID: string,
   +accessToken: string,
   +deviceAppVersion?: string,
-  +userId: string,
+  +userID: string,
 };
 
 export type TBKeyserverConnectionInitializationMessage = {
@@ -39,14 +39,14 @@
 
 export type TBRefreshKeysRequest = {
   +type: 'RefreshKeyRequest',
-  +deviceId: string,
+  +deviceID: string,
   +numberOfKeys: number,
 };
 
 export const refreshKeysTBMessageValidator: TInterface<TBRefreshKeysRequest> =
   tShape<TBRefreshKeysRequest>({
     type: tString('RefreshKeyRequest'),
-    deviceId: t.String,
+    deviceID: t.String,
     numberOfKeys: t.Number,
   });
 
diff --git a/services/commtest/tests/tunnelbroker_integration_test.rs b/services/commtest/tests/tunnelbroker_integration_test.rs
--- a/services/commtest/tests/tunnelbroker_integration_test.rs
+++ b/services/commtest/tests/tunnelbroker_integration_test.rs
@@ -19,8 +19,8 @@
   let session_request = r#"{
       "type": "sessionRequest",
       "accessToken": "xkdeifjsld",
-      "deviceId": "foo",
-      "userId": "alice",
+      "deviceID": "foo",
+      "userID": "alice",
       "deviceType": "keyserver"
     }"#;
 
@@ -101,7 +101,7 @@
   let session_request = r#"{
       "type": "sessionRequest",
       "accessToken": "xkdexfjsld",
-      "deviceId": "bar",
+      "deviceID": "bar",
       "deviceType": "keyserver"
     }"#;
 
diff --git a/shared/tunnelbroker_messages/src/messages/keys.rs b/shared/tunnelbroker_messages/src/messages/keys.rs
--- a/shared/tunnelbroker_messages/src/messages/keys.rs
+++ b/shared/tunnelbroker_messages/src/messages/keys.rs
@@ -5,6 +5,7 @@
 #[derive(Serialize, Deserialize, PartialEq, Debug)]
 #[serde(tag = "type", rename_all = "camelCase")]
 pub struct RefreshKeyRequest {
+  #[serde(rename = "deviceID")]
   pub device_id: String,
   pub number_of_keys: u32,
 }
@@ -17,7 +18,7 @@
   fn test_refresh_deserialization() {
     let example_payload = r#"{
       "type": "RefreshKeyRequest",
-      "deviceId": "adfjEDFS",
+      "deviceID": "adfjEDFS",
       "numberOfKeys": 6
     }"#;
 
diff --git a/shared/tunnelbroker_messages/src/messages/session.rs b/shared/tunnelbroker_messages/src/messages/session.rs
--- a/shared/tunnelbroker_messages/src/messages/session.rs
+++ b/shared/tunnelbroker_messages/src/messages/session.rs
@@ -32,8 +32,10 @@
 #[derive(Serialize, Deserialize)]
 #[serde(tag = "type", rename_all = "camelCase")]
 pub struct ConnectionInitializationMessage {
+  #[serde(rename = "deviceID")]
   pub device_id: String,
   pub access_token: String,
+  #[serde(rename = "userID")]
   pub user_id: String,
   pub notify_token: Option<String>,
   pub device_type: DeviceTypes,
@@ -55,8 +57,8 @@
     let example_payload = r#"{
       "type": "sessionRequest",
       "accessToken": "xkdeifjsld",
-      "deviceId": "foo",
-      "userId": "alice",
+      "deviceID": "foo",
+      "userID": "alice",
       "deviceType": "keyserver"
     }"#;