diff --git a/federation/src/graphql/api/1_0/resolver/AuthenticationResolver.ts b/federation/src/graphql/api/1_0/resolver/AuthenticationResolver.ts
index 73eb70d26..3c62c7bef 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, { nullable: true })
+  @Mutation(() => String)
   async authenticate(
     @Arg('data')
     args: EncryptedTransferArgs,