diff --git a/package.json b/package.json
index e4fd7016..692b34ac 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@orionprotocol/sdk",
-  "version": "0.22.0",
+  "version": "0.22.1-rc1",
   "description": "Orion Protocol SDK",
   "main": "./lib/index.cjs",
   "module": "./lib/index.js",
diff --git a/src/services/Aggregator/ws/schemas/addressUpdateSchema.ts b/src/services/Aggregator/ws/schemas/addressUpdateSchema.ts
index 1e3e8d99..2edde4d8 100644
--- a/src/services/Aggregator/ws/schemas/addressUpdateSchema.ts
+++ b/src/services/Aggregator/ws/schemas/addressUpdateSchema.ts
@@ -10,7 +10,7 @@ const baseAddressUpdate = baseMessageSchema.extend({
   id: z.string(),
   T: z.literal(MessageType.ADDRESS_UPDATE),
   S: z.string(), // subscription
-  uc: z.array(z.enum(['b', 'o'])), // update content
+  uc: z.array(z.enum(['b', 'o']).nullable()), // update content
 });
 
 const subOrderSchema = z.object({
@@ -121,7 +121,7 @@ export const fullOrderSchema = z.object({
 
 const updateMessageSchema = baseAddressUpdate.extend({
   k: z.literal('u'), // kind of message: "u" - updates
-  uc: z.array(z.enum(['b', 'o'])), // update content: "o" - orders updates, "b" - balance updates
+  uc: z.array(z.enum(['b', 'o']).nullable()), // update content: "o" - orders updates, "b" - balance updates
   b: balancesSchema.optional(),
   o: z.tuple([fullOrderSchema.or(orderUpdateSchema)]).optional(),
 });