diff --git a/federation/src/graphql/api/1_0/resolver/AuthenticationResolver.ts b/federation/src/graphql/api/1_0/resolver/AuthenticationResolver.ts
index 3c62c7bef..4c14360e9 100644
--- a/federation/src/graphql/api/1_0/resolver/AuthenticationResolver.ts
+++ b/federation/src/graphql/api/1_0/resolver/AuthenticationResolver.ts
@@ -109,7 +109,7 @@ export class AuthenticationResolver {
     }
   }
 
-  @Mutation(() => String)
+  @Mutation(() => String, { nullable: true })
   async authenticate(
     @Arg('data')
     args: EncryptedTransferArgs,
@@ -125,7 +125,7 @@ export class AuthenticationResolver {
         // no infos to the caller
         return null
       }
-      if (!uint32Schema.safeParse(authArgs.oneTimeCode).success) {
+      if (!uint32Schema.safeParse(Number(authArgs.oneTimeCode)).success) {
         const errmsg = `invalid oneTimeCode: ${authArgs.oneTimeCode} for community with publicKey ${authArgs.publicKey}, expect uint32`
         methodLogger.error(errmsg)
         // no infos to the caller
diff --git a/shared/src/schema/base.schema.test.ts b/shared/src/schema/base.schema.test.ts
index 3e56a9a22..d12f2a3b4 100644
--- a/shared/src/schema/base.schema.test.ts
+++ b/shared/src/schema/base.schema.test.ts
@@ -1,5 +1,5 @@
 import { describe, expect, it } from 'bun:test'
-import { uuidv4Schema } from './base.schema'
+import { uuidv4Schema, uint32Schema } from './base.schema'
 import { v4 as uuidv4 } from 'uuid'
 
 describe('uuidv4 schema', () => {
@@ -10,3 +10,15 @@ describe('uuidv4 schema', () => {
     }
   })
 })
+
+describe('uint32 schema', () => {
+  it('should validate uint32 (40x)', () => {
+    for (let i = 0; i < 40; i++) {
+      const uint32 = Math.floor(Math.random() * 4294967295)
+      expect(uint32Schema.safeParse(uint32).success).toBeTruthy()
+    }
+  })
+  it('should validate 2092352810', () => {
+    expect(uint32Schema.safeParse(2092352810).success).toBeTruthy()
+  })
+})