diff --git a/src/idz/decoder/_defs.ts b/src/idz/decoder/_defs.ts
deleted file mode 100644
index b0eaca5..0000000
--- a/src/idz/decoder/_defs.ts
+++ /dev/null
@@ -1,5 +0,0 @@
-// Quasi-nominative typing "brands".
-// The double-underscore properties never actually exist at runtime, we just
-// pretend they do.
-
-export type RequestCode = number & { __requestId: null };
diff --git a/src/idz/decoder/checkTeamName.ts b/src/idz/decoder/checkTeamName.ts
index 78ab285..5d8ed94 100644
--- a/src/idz/decoder/checkTeamName.ts
+++ b/src/idz/decoder/checkTeamName.ts
@@ -1,7 +1,6 @@
-import { RequestCode } from "./_defs";
 import { CheckTeamNameRequest } from "../request/checkTeamName";
 
-checkTeamName.msgCode = 0x00a2 as RequestCode;
+checkTeamName.msgCode = 0x00a2;
 checkTeamName.msgLen = 0x0040;
 
 export function checkTeamName(buf: Buffer): CheckTeamNameRequest {
diff --git a/src/idz/decoder/createAutoTeam.ts b/src/idz/decoder/createAutoTeam.ts
index 07f17f8..0c188d1 100644
--- a/src/idz/decoder/createAutoTeam.ts
+++ b/src/idz/decoder/createAutoTeam.ts
@@ -1,8 +1,7 @@
-import { RequestCode } from "./_defs";
 import { CreateAutoTeamRequest } from "../request/createAutoTeam";
 import { AimeId } from "../../model";
 
-createAutoTeam.msgCode = 0x007b as RequestCode;
+createAutoTeam.msgCode = 0x007b;
 createAutoTeam.msgLen = 0x0010;
 
 export function createAutoTeam(buf: Buffer): CreateAutoTeamRequest {
diff --git a/src/idz/decoder/createProfile.ts b/src/idz/decoder/createProfile.ts
index 74df56e..0c1f130 100644
--- a/src/idz/decoder/createProfile.ts
+++ b/src/idz/decoder/createProfile.ts
@@ -2,11 +2,10 @@ import iconv from "iconv-lite";
 
 import { car } from "./_car";
 import { chara } from "./_chara";
-import { RequestCode } from "./_defs";
 import { CreateProfileRequest } from "../request/createProfile";
 import { AimeId } from "../../model";
 
-createProfile.msgCode = 0x0066 as RequestCode;
+createProfile.msgCode = 0x0066;
 createProfile.msgLen = 0x00c0;
 
 export function createProfile(buf: Buffer): CreateProfileRequest {
diff --git a/src/idz/decoder/createTeam.ts b/src/idz/decoder/createTeam.ts
index d568c90..a9133ef 100644
--- a/src/idz/decoder/createTeam.ts
+++ b/src/idz/decoder/createTeam.ts
@@ -1,10 +1,9 @@
 import iconv from "iconv-lite";
 
-import { RequestCode } from "./_defs";
 import { CreateTeamRequest } from "../request/createTeam";
 import { AimeId } from "../../model";
 
-createTeam.msgCode = 0x0071 as RequestCode;
+createTeam.msgCode = 0x0071;
 createTeam.msgLen = 0x0050;
 
 export function createTeam(buf: Buffer): CreateTeamRequest {
diff --git a/src/idz/decoder/discoverProfile.ts b/src/idz/decoder/discoverProfile.ts
index 9d5ee2e..4658727 100644
--- a/src/idz/decoder/discoverProfile.ts
+++ b/src/idz/decoder/discoverProfile.ts
@@ -1,8 +1,7 @@
-import { RequestCode } from "./_defs";
 import { DiscoverProfileRequest } from "../request/discoverProfile";
 import { AimeId } from "../../model";
 
-discoverProfile.msgCode = 0x006b as RequestCode;
+discoverProfile.msgCode = 0x006b;
 discoverProfile.msgLen = 0x0010;
 
 export function discoverProfile(buf: Buffer): DiscoverProfileRequest {
diff --git a/src/idz/decoder/index.ts b/src/idz/decoder/index.ts
index 63ff947..337277f 100644
--- a/src/idz/decoder/index.ts
+++ b/src/idz/decoder/index.ts
@@ -42,7 +42,6 @@ import {
   updateStoryClearNum1,
   updateStoryClearNum2,
 } from "./updateStoryClearNum";
-import { RequestCode } from "./_defs";
 import { Request } from "../request";
 import { updateResult } from "./updateResult";
 import { updateTeamPoints } from "./updateTeamPoints";
@@ -51,7 +50,7 @@ import { updateUserLog } from "./updateUserLog";
 import { lockProfileExtend } from "./lockProfileExtend";
 
 export type ReaderFn = ((buf: Buffer) => Request) & {
-  msgCode: RequestCode;
+  msgCode: number;
   msgLen: number;
 };
 
@@ -109,8 +108,8 @@ const funcList: ReaderFn[] = [
   updateUserLog,
 ];
 
-const readerFns = new Map<RequestCode, ReaderFn>();
-const msgLengths = new Map<RequestCode, number>();
+const readerFns = new Map<number, ReaderFn>();
+const msgLengths = new Map<number, number>();
 
 for (const fn of funcList) {
   readerFns.set(fn.msgCode, fn);
@@ -164,7 +163,7 @@ export class Decoder extends Transform {
       return callback(null);
     }
 
-    const msgCode = this.state.readUInt16LE(0x30) as RequestCode;
+    const msgCode = this.state.readUInt16LE(0x30);
     const msgLen = msgLengths.get(msgCode);
 
     if (msgLen === undefined) {
diff --git a/src/idz/decoder/load2on2.ts b/src/idz/decoder/load2on2.ts
index def366c..bd52e4a 100644
--- a/src/idz/decoder/load2on2.ts
+++ b/src/idz/decoder/load2on2.ts
@@ -1,10 +1,9 @@
-import { RequestCode } from "./_defs";
 import { ExtId } from "../model/base";
 import { Team } from "../model/team";
 import { Load2on2Request1, Load2on2Request2 } from "../request/load2on2";
 import { AimeId } from "../../model";
 
-load2on2_v1.msgCode = 0x00b0 as RequestCode;
+load2on2_v1.msgCode = 0x00b0;
 load2on2_v1.msgLen = 0x0010;
 
 export function load2on2_v1(buf: Buffer): Load2on2Request1 {
@@ -17,7 +16,7 @@ export function load2on2_v1(buf: Buffer): Load2on2Request1 {
   };
 }
 
-load2on2_v2.msgCode = 0x0132 as RequestCode;
+load2on2_v2.msgCode = 0x0132;
 load2on2_v2.msgLen = 0x0010;
 
 export function load2on2_v2(buf: Buffer): Load2on2Request2 {
diff --git a/src/idz/decoder/loadConfig.ts b/src/idz/decoder/loadConfig.ts
index c59fd1a..41bf2e9 100644
--- a/src/idz/decoder/loadConfig.ts
+++ b/src/idz/decoder/loadConfig.ts
@@ -1,7 +1,6 @@
-import { RequestCode } from "./_defs";
 import { LoadConfigRequest } from "../request/loadConfig";
 
-loadConfig.msgCode = 0x0004 as RequestCode;
+loadConfig.msgCode = 0x0004;
 loadConfig.msgLen = 0x0050;
 
 export function loadConfig(): LoadConfigRequest {
diff --git a/src/idz/decoder/loadConfig2.ts b/src/idz/decoder/loadConfig2.ts
index ceaec63..07b919d 100644
--- a/src/idz/decoder/loadConfig2.ts
+++ b/src/idz/decoder/loadConfig2.ts
@@ -1,7 +1,6 @@
-import { RequestCode } from "./_defs";
 import { LoadConfigRequest2 } from "../request/loadConfig2";
 
-loadConfig2.msgCode = 0x00ab as RequestCode;
+loadConfig2.msgCode = 0x00ab;
 loadConfig2.msgLen = 0x0010;
 
 export function loadConfig2(): LoadConfigRequest2 {
diff --git a/src/idz/decoder/loadEventInfo.ts b/src/idz/decoder/loadEventInfo.ts
index 7e67f8d..ce2393f 100644
--- a/src/idz/decoder/loadEventInfo.ts
+++ b/src/idz/decoder/loadEventInfo.ts
@@ -1,8 +1,7 @@
-import { RequestCode } from "./_defs";
 import { LoadEventInfoRequest } from "../request/loadEventInfo";
 import { AimeId } from "../../model";
 
-loadEventInfo.msgCode = 0x00be as RequestCode;
+loadEventInfo.msgCode = 0x00be;
 loadEventInfo.msgLen = 0x0010;
 
 export function loadEventInfo(buf: Buffer): LoadEventInfoRequest {
diff --git a/src/idz/decoder/loadGacha.ts b/src/idz/decoder/loadGacha.ts
index 86cb50a..375a155 100644
--- a/src/idz/decoder/loadGacha.ts
+++ b/src/idz/decoder/loadGacha.ts
@@ -1,8 +1,7 @@
-import { RequestCode } from "./_defs";
 import { LoadGachaRequest } from "../request/loadGacha";
 import { AimeId } from "../../model";
 
-loadGacha.msgCode = 0x00c1 as RequestCode;
+loadGacha.msgCode = 0x00c1;
 loadGacha.msgLen = 0x0010;
 
 export function loadGacha(buf: Buffer): LoadGachaRequest {
diff --git a/src/idz/decoder/loadGarage.ts b/src/idz/decoder/loadGarage.ts
index dae436f..3961619 100644
--- a/src/idz/decoder/loadGarage.ts
+++ b/src/idz/decoder/loadGarage.ts
@@ -1,8 +1,7 @@
-import { RequestCode } from "./_defs";
 import { LoadGarageRequest } from "../request/loadGarage";
 import { AimeId } from "../../model";
 
-loadGarage.msgCode = 0x0090 as RequestCode;
+loadGarage.msgCode = 0x0090;
 loadGarage.msgLen = 0x0010;
 
 export function loadGarage(buf: Buffer): LoadGarageRequest {
diff --git a/src/idz/decoder/loadGeneralReward.ts b/src/idz/decoder/loadGeneralReward.ts
index cf8b47d..2f5dd23 100644
--- a/src/idz/decoder/loadGeneralReward.ts
+++ b/src/idz/decoder/loadGeneralReward.ts
@@ -1,11 +1,10 @@
-import { RequestCode } from "./_defs";
 import {
   LoadGeneralRewardRequest1,
   LoadGeneralRewardRequest2,
 } from "../request/loadGeneralReward";
 import { AimeId } from "../../model";
 
-loadGeneralReward1.msgCode = 0x009c as RequestCode;
+loadGeneralReward1.msgCode = 0x009c;
 loadGeneralReward1.msgLen = 0x0010;
 
 export function loadGeneralReward1(buf: Buffer): LoadGeneralRewardRequest1 {
@@ -16,7 +15,7 @@ export function loadGeneralReward1(buf: Buffer): LoadGeneralRewardRequest1 {
   };
 }
 
-loadGeneralReward2.msgCode = 0x013b as RequestCode;
+loadGeneralReward2.msgCode = 0x013b;
 loadGeneralReward2.msgLen = 0x0010;
 
 export function loadGeneralReward2(buf: Buffer): LoadGeneralRewardRequest2 {
diff --git a/src/idz/decoder/loadGhost.ts b/src/idz/decoder/loadGhost.ts
index d28f2bd..2fcdcbc 100644
--- a/src/idz/decoder/loadGhost.ts
+++ b/src/idz/decoder/loadGhost.ts
@@ -1,7 +1,6 @@
-import { RequestCode } from "./_defs";
 import { LoadGhostRequest } from "../request/loadGhost";
 
-loadGhost.msgCode = 0x00a0 as RequestCode;
+loadGhost.msgCode = 0x00a0;
 loadGhost.msgLen = 0x0010;
 
 export function loadGhost(buf: Buffer): LoadGhostRequest {
diff --git a/src/idz/decoder/loadProfile.ts b/src/idz/decoder/loadProfile.ts
index edc88b7..1b5fbfa 100644
--- a/src/idz/decoder/loadProfile.ts
+++ b/src/idz/decoder/loadProfile.ts
@@ -1,11 +1,10 @@
-import { RequestCode } from "./_defs";
 import {
   LoadProfileRequest2,
   LoadProfileRequest3,
 } from "../request/loadProfile";
 import { AimeId } from "../../model";
 
-loadProfile2.msgCode = 0x0067 as RequestCode;
+loadProfile2.msgCode = 0x0067;
 loadProfile2.msgLen = 0x0020;
 
 export function loadProfile2(buf: Buffer): LoadProfileRequest2 {
@@ -17,7 +16,7 @@ export function loadProfile2(buf: Buffer): LoadProfileRequest2 {
   };
 }
 
-loadProfile3.msgCode = 0x0012f as RequestCode;
+loadProfile3.msgCode = 0x0012f;
 loadProfile3.msgLen = 0x0020;
 
 export function loadProfile3(buf: Buffer): LoadProfileRequest3 {
diff --git a/src/idz/decoder/loadRewardTable.ts b/src/idz/decoder/loadRewardTable.ts
index 6007271..4e2b0d0 100644
--- a/src/idz/decoder/loadRewardTable.ts
+++ b/src/idz/decoder/loadRewardTable.ts
@@ -1,7 +1,6 @@
-import { RequestCode } from "./_defs";
 import { LoadRewardTableRequest } from "../request/loadRewardTable";
 
-loadRewardTable.msgCode = 0x0086 as RequestCode;
+loadRewardTable.msgCode = 0x0086;
 loadRewardTable.msgLen = 0x0010;
 
 export function loadRewardTable(): LoadRewardTableRequest {
diff --git a/src/idz/decoder/loadServerList.ts b/src/idz/decoder/loadServerList.ts
index d444eba..2884622 100644
--- a/src/idz/decoder/loadServerList.ts
+++ b/src/idz/decoder/loadServerList.ts
@@ -1,7 +1,6 @@
-import { RequestCode } from "./_defs";
 import { LoadServerListRequest } from "../request/loadServerList";
 
-loadServerList.msgCode = 0x0006 as RequestCode;
+loadServerList.msgCode = 0x0006;
 loadServerList.msgLen = 0x0020;
 
 export function loadServerList(): LoadServerListRequest {
diff --git a/src/idz/decoder/loadStocker.ts b/src/idz/decoder/loadStocker.ts
index ab41d29..f708960 100644
--- a/src/idz/decoder/loadStocker.ts
+++ b/src/idz/decoder/loadStocker.ts
@@ -1,8 +1,7 @@
-import { RequestCode } from "./_defs";
 import { LoadStockerRequest } from "../request/loadStocker";
 import { AimeId } from "../../model";
 
-loadStocker.msgCode = 0x00a7 as RequestCode;
+loadStocker.msgCode = 0x00a7;
 loadStocker.msgLen = 0x0010;
 
 export function loadStocker(buf: Buffer): LoadStockerRequest {
diff --git a/src/idz/decoder/loadTeam.ts b/src/idz/decoder/loadTeam.ts
index a94cd1b..ba99a49 100644
--- a/src/idz/decoder/loadTeam.ts
+++ b/src/idz/decoder/loadTeam.ts
@@ -1,9 +1,8 @@
-import { RequestCode } from "./_defs";
 import { LoadTeamRequest } from "../request/loadTeam";
 import { ExtId } from "../model/base";
 import { Team } from "../model/team";
 
-loadTeam.msgCode = 0x0077 as RequestCode;
+loadTeam.msgCode = 0x0077;
 loadTeam.msgLen = 0x0010;
 
 export function loadTeam(buf: Buffer): LoadTeamRequest {
diff --git a/src/idz/decoder/loadTeamRanking.ts b/src/idz/decoder/loadTeamRanking.ts
index 13b368a..736f71b 100644
--- a/src/idz/decoder/loadTeamRanking.ts
+++ b/src/idz/decoder/loadTeamRanking.ts
@@ -1,7 +1,6 @@
-import { RequestCode } from "./_defs";
 import { LoadTeamRankingRequest } from "../request/loadTeamRanking";
 
-loadTeamRanking.msgCode = 0x00b9 as RequestCode;
+loadTeamRanking.msgCode = 0x00b9;
 loadTeamRanking.msgLen = 0x0010;
 
 export function loadTeamRanking(buf: Buffer): LoadTeamRankingRequest {
@@ -12,7 +11,7 @@ export function loadTeamRanking(buf: Buffer): LoadTeamRankingRequest {
 
 // not sure what the difference is...
 
-loadTeamRanking2.msgCode = 0x00bb as RequestCode;
+loadTeamRanking2.msgCode = 0x00bb;
 loadTeamRanking2.msgLen = 0x0010;
 
 export function loadTeamRanking2(buf: Buffer): LoadTeamRankingRequest {
diff --git a/src/idz/decoder/loadTopTen1.ts b/src/idz/decoder/loadTopTen1.ts
index ecf2e3c..7b75590 100644
--- a/src/idz/decoder/loadTopTen1.ts
+++ b/src/idz/decoder/loadTopTen1.ts
@@ -1,4 +1,3 @@
-import { RequestCode } from "./_defs";
 import { ExtId, RouteNo } from "../model/base";
 import { Team } from "../model/team";
 import {
@@ -7,7 +6,7 @@ import {
 } from "../request/loadTopTen";
 import { AimeId } from "../../model";
 
-loadTopTen1.msgCode = 0x00b5 as RequestCode;
+loadTopTen1.msgCode = 0x00b5;
 loadTopTen1.msgLen = 0x00e0;
 
 export function loadTopTen1(buf: Buffer): LoadTopTenRequest {
diff --git a/src/idz/decoder/loadTopTen2.ts b/src/idz/decoder/loadTopTen2.ts
index 088bdda..ca73160 100644
--- a/src/idz/decoder/loadTopTen2.ts
+++ b/src/idz/decoder/loadTopTen2.ts
@@ -1,4 +1,3 @@
-import { RequestCode } from "./_defs";
 import { ExtId, RouteNo } from "../model/base";
 import { Team } from "../model/team";
 import {
@@ -7,7 +6,7 @@ import {
 } from "../request/loadTopTen";
 import { AimeId } from "../../model";
 
-loadTopTen2.msgCode = 0x012c as RequestCode;
+loadTopTen2.msgCode = 0x012c;
 loadTopTen2.msgLen = 0x0110;
 
 export function loadTopTen2(buf: Buffer): LoadTopTenRequest {
diff --git a/src/idz/decoder/lockGarage.ts b/src/idz/decoder/lockGarage.ts
index 0a211e0..f4d34fe 100644
--- a/src/idz/decoder/lockGarage.ts
+++ b/src/idz/decoder/lockGarage.ts
@@ -1,7 +1,6 @@
-import { RequestCode } from "./_defs";
 import { LockGarageRequest } from "../request/lockGarage";
 
-lockGarage.msgCode = 0x00a9 as RequestCode;
+lockGarage.msgCode = 0x00a9;
 lockGarage.msgLen = 0x0010;
 
 export function lockGarage(buf: Buffer): LockGarageRequest {
diff --git a/src/idz/decoder/lockProfile.ts b/src/idz/decoder/lockProfile.ts
index e87db39..e461e3d 100644
--- a/src/idz/decoder/lockProfile.ts
+++ b/src/idz/decoder/lockProfile.ts
@@ -1,7 +1,6 @@
-import { RequestCode } from "./_defs";
 import { LockProfileRequest } from "../request/lockProfile";
 
-lockProfile.msgCode = 0x0069 as RequestCode;
+lockProfile.msgCode = 0x0069;
 lockProfile.msgLen = 0x0020;
 
 export function lockProfile(buf: Buffer): LockProfileRequest {
diff --git a/src/idz/decoder/lockProfileExtend.ts b/src/idz/decoder/lockProfileExtend.ts
index 6a0f11a..4810445 100644
--- a/src/idz/decoder/lockProfileExtend.ts
+++ b/src/idz/decoder/lockProfileExtend.ts
@@ -1,8 +1,7 @@
-import { RequestCode } from "./_defs";
 import { LockProfileExtendRequest } from "../request/lockProfileExtend";
 import { AimeId } from "../../model";
 
-lockProfileExtend.msgCode = 0x006d as RequestCode;
+lockProfileExtend.msgCode = 0x006d;
 lockProfileExtend.msgLen = 0x0020;
 
 export function lockProfileExtend(buf: Buffer): LockProfileExtendRequest {
diff --git a/src/idz/decoder/msg00AD.ts b/src/idz/decoder/msg00AD.ts
index a974cda..e2504fc 100644
--- a/src/idz/decoder/msg00AD.ts
+++ b/src/idz/decoder/msg00AD.ts
@@ -1,7 +1,6 @@
-import { RequestCode } from "./_defs";
 import { Message00AD } from "../request/msg00AD";
 
-msg00AD.msgCode = 0x00ad as RequestCode;
+msg00AD.msgCode = 0x00ad;
 msg00AD.msgLen = 0x061c;
 
 export function msg00AD(buf: Buffer): Message00AD {
diff --git a/src/idz/decoder/saveExpedition.ts b/src/idz/decoder/saveExpedition.ts
index 1a6e7d4..e977d8a 100644
--- a/src/idz/decoder/saveExpedition.ts
+++ b/src/idz/decoder/saveExpedition.ts
@@ -1,10 +1,9 @@
-import { RequestCode } from "./_defs";
 import {
   SaveExpeditionRequest1,
   SaveExpeditionRequest2,
 } from "../request/saveExpedition";
 
-saveExpedition1.msgCode = 0x008c as RequestCode;
+saveExpedition1.msgCode = 0x008c;
 saveExpedition1.msgLen = 0x0010;
 
 export function saveExpedition1(buf: Buffer): SaveExpeditionRequest1 {
@@ -15,7 +14,7 @@ export function saveExpedition1(buf: Buffer): SaveExpeditionRequest1 {
   };
 }
 
-saveExpedition2.msgCode = 0x013f as RequestCode;
+saveExpedition2.msgCode = 0x013f;
 saveExpedition2.msgLen = 0x0010;
 
 export function saveExpedition2(buf: Buffer): SaveExpeditionRequest2 {
diff --git a/src/idz/decoder/saveGarage.ts b/src/idz/decoder/saveGarage.ts
index 6eae71e..fae0671 100644
--- a/src/idz/decoder/saveGarage.ts
+++ b/src/idz/decoder/saveGarage.ts
@@ -1,8 +1,7 @@
 import { car } from "./_car";
-import { RequestCode } from "./_defs";
 import { SaveGarageRequest } from "../request/saveGarage";
 
-saveGarage.msgCode = 0x008e as RequestCode;
+saveGarage.msgCode = 0x008e;
 saveGarage.msgLen = 0x0090;
 
 export function saveGarage(buf: Buffer): SaveGarageRequest {
diff --git a/src/idz/decoder/saveNewCar.ts b/src/idz/decoder/saveNewCar.ts
index c857d6d..c252ba6 100644
--- a/src/idz/decoder/saveNewCar.ts
+++ b/src/idz/decoder/saveNewCar.ts
@@ -1,9 +1,8 @@
 import { car } from "./_car";
-import { RequestCode } from "./_defs";
 import { SaveNewCarRequest } from "../request/saveNewCar";
 import { AimeId } from "../../model";
 
-saveNewCar.msgCode = 0x0079 as RequestCode;
+saveNewCar.msgCode = 0x0079;
 saveNewCar.msgLen = 0x0090;
 
 export function saveNewCar(buf: Buffer): SaveNewCarRequest {
diff --git a/src/idz/decoder/saveProfile2.ts b/src/idz/decoder/saveProfile2.ts
index 1f7147a..bfb567b 100644
--- a/src/idz/decoder/saveProfile2.ts
+++ b/src/idz/decoder/saveProfile2.ts
@@ -1,12 +1,11 @@
 import { car } from "./_car";
 import { mission } from "./_mission";
-import { RequestCode } from "./_defs";
-import { BackgroundCode, CourseNo, ExtId, TitleCode } from "../model/base";
+import { BackgroundCode, CourseNo, TitleCode } from "../model/base";
 import { SaveProfileRequest2 } from "../request/saveProfile";
 import { bitmap } from "./_bitmap";
 import { AimeId } from "../../model";
 
-saveProfile2.msgCode = 0x0068 as RequestCode;
+saveProfile2.msgCode = 0x0068;
 saveProfile2.msgLen = 0x0940;
 
 export function saveProfile2(buf: Buffer): SaveProfileRequest2 {
diff --git a/src/idz/decoder/saveProfile3.ts b/src/idz/decoder/saveProfile3.ts
index 0af3976..013c8a3 100644
--- a/src/idz/decoder/saveProfile3.ts
+++ b/src/idz/decoder/saveProfile3.ts
@@ -1,12 +1,11 @@
 import { car } from "./_car";
 import { mission } from "./_mission";
-import { RequestCode } from "./_defs";
 import { BackgroundCode, CourseNo, TitleCode } from "../model/base";
 import { SaveProfileRequest2 } from "../request/saveProfile";
 import { bitmap } from "./_bitmap";
 import { AimeId } from "../../model";
 
-saveProfile3.msgCode = 0x0138 as RequestCode;
+saveProfile3.msgCode = 0x0138;
 saveProfile3.msgLen = 0x0a70;
 
 export function saveProfile3(buf: Buffer): SaveProfileRequest2 {
diff --git a/src/idz/decoder/saveSettings.ts b/src/idz/decoder/saveSettings.ts
index 3e471a7..f52b13d 100644
--- a/src/idz/decoder/saveSettings.ts
+++ b/src/idz/decoder/saveSettings.ts
@@ -1,8 +1,7 @@
-import { RequestCode } from "./_defs";
 import { SaveSettingsRequest } from "../request/saveSettings";
 import { AimeId } from "../../model";
 
-saveSettings.msgCode = 0x00a5 as RequestCode;
+saveSettings.msgCode = 0x00a5;
 saveSettings.msgLen = 0x0020;
 
 export function saveSettings(buf: Buffer): SaveSettingsRequest {
diff --git a/src/idz/decoder/saveStocker.ts b/src/idz/decoder/saveStocker.ts
index 8951e3c..035afca 100644
--- a/src/idz/decoder/saveStocker.ts
+++ b/src/idz/decoder/saveStocker.ts
@@ -1,11 +1,10 @@
 import { bitmap } from "./_bitmap";
 import { chara } from "./_chara";
-import { RequestCode } from "./_defs";
 import { CarSelector } from "../model/car";
 import { SaveStockerRequest } from "../request/saveStocker";
 import { AimeId } from "../../model";
 
-saveStocker.msgCode = 0x00a6 as RequestCode;
+saveStocker.msgCode = 0x00a6;
 saveStocker.msgLen = 0x00c0;
 
 export function saveStocker(buf: Buffer): SaveStockerRequest {
diff --git a/src/idz/decoder/saveTeamBanner.ts b/src/idz/decoder/saveTeamBanner.ts
index fe91b09..54afa4b 100644
--- a/src/idz/decoder/saveTeamBanner.ts
+++ b/src/idz/decoder/saveTeamBanner.ts
@@ -1,9 +1,8 @@
-import { RequestCode } from "./_defs";
 import { SaveTeamBannerRequest } from "../request/saveTeamBanner";
 import { ExtId } from "../model/base";
 import { Team } from "../model/team";
 
-saveTeamBanner.msgCode = 0x0089 as RequestCode;
+saveTeamBanner.msgCode = 0x0089;
 saveTeamBanner.msgLen = 0x0010;
 
 export function saveTeamBanner(buf: Buffer): SaveTeamBannerRequest {
diff --git a/src/idz/decoder/saveTimeAttack.ts b/src/idz/decoder/saveTimeAttack.ts
index 7546d0e..171abbf 100644
--- a/src/idz/decoder/saveTimeAttack.ts
+++ b/src/idz/decoder/saveTimeAttack.ts
@@ -1,4 +1,3 @@
-import { RequestCode } from "./_defs";
 import { RouteNo } from "../model/base";
 import { CarSelector } from "../model/car";
 import { SaveTimeAttackRequest } from "../request/saveTimeAttack";
@@ -36,14 +35,14 @@ function saveTimeAttack(buf: Buffer): SaveTimeAttackRequest {
 // request code..? Even the response uses the same response code, despite
 // the request codes differing.
 
-saveTimeAttack1.msgCode = 0x00cd as RequestCode;
+saveTimeAttack1.msgCode = 0x00cd;
 saveTimeAttack1.msgLen = 0x0080;
 
 export function saveTimeAttack1(buf: Buffer): SaveTimeAttackRequest {
   return saveTimeAttack(buf);
 }
 
-saveTimeAttack2.msgCode = 0x0136 as RequestCode;
+saveTimeAttack2.msgCode = 0x0136;
 saveTimeAttack2.msgLen = 0x0080;
 
 export function saveTimeAttack2(buf: Buffer): SaveTimeAttackRequest {
diff --git a/src/idz/decoder/saveTopic.ts b/src/idz/decoder/saveTopic.ts
index e93c9e5..6f75fde 100644
--- a/src/idz/decoder/saveTopic.ts
+++ b/src/idz/decoder/saveTopic.ts
@@ -1,7 +1,6 @@
-import { RequestCode } from "./_defs";
 import { SaveTopicRequest } from "../request/saveTopic";
 
-saveTopic.msgCode = 0x009a as RequestCode;
+saveTopic.msgCode = 0x009a;
 saveTopic.msgLen = 0x0010;
 
 export function saveTopic(buf: Buffer): SaveTopicRequest {
diff --git a/src/idz/decoder/unlockProfile.ts b/src/idz/decoder/unlockProfile.ts
index 345dc3a..864d0e4 100644
--- a/src/idz/decoder/unlockProfile.ts
+++ b/src/idz/decoder/unlockProfile.ts
@@ -1,7 +1,6 @@
-import { RequestCode } from "./_defs";
 import { UnlockProfileRequest } from "../request/unlockProfile";
 
-unlockProfile.msgCode = 0x006f as RequestCode;
+unlockProfile.msgCode = 0x006f;
 unlockProfile.msgLen = 0x0020;
 
 export function unlockProfile(buf: Buffer): UnlockProfileRequest {
diff --git a/src/idz/decoder/updateProvisionalStoreRank.ts b/src/idz/decoder/updateProvisionalStoreRank.ts
index db11cb3..2986872 100644
--- a/src/idz/decoder/updateProvisionalStoreRank.ts
+++ b/src/idz/decoder/updateProvisionalStoreRank.ts
@@ -1,7 +1,6 @@
-import { RequestCode } from "./_defs";
 import { UpdateProvisionalStoreRankRequest } from "../request/updateProvisionalStoreRank";
 
-updateProvisionalStoreRank.msgCode = 0x0082 as RequestCode;
+updateProvisionalStoreRank.msgCode = 0x0082;
 updateProvisionalStoreRank.msgLen = 0x0010;
 
 export function updateProvisionalStoreRank(
diff --git a/src/idz/decoder/updateResult.ts b/src/idz/decoder/updateResult.ts
index 2aeb095..ea79ff5 100644
--- a/src/idz/decoder/updateResult.ts
+++ b/src/idz/decoder/updateResult.ts
@@ -1,7 +1,6 @@
-import { RequestCode } from "./_defs";
 import { UpdateResultRequest } from "../request/updateResult";
 
-updateResult.msgCode = 0x00cc as RequestCode;
+updateResult.msgCode = 0x00cc;
 updateResult.msgLen = 0x0030;
 
 export function updateResult(buf: Buffer): UpdateResultRequest {
diff --git a/src/idz/decoder/updateStoryClearNum.ts b/src/idz/decoder/updateStoryClearNum.ts
index ae5ce8d..720205d 100644
--- a/src/idz/decoder/updateStoryClearNum.ts
+++ b/src/idz/decoder/updateStoryClearNum.ts
@@ -1,10 +1,9 @@
-import { RequestCode } from "./_defs";
 import {
   UpdateStoryClearNumRequest1,
   UpdateStoryClearNumRequest2,
 } from "../request/updateStoryClearNum";
 
-updateStoryClearNum1.msgCode = 0x007f as RequestCode;
+updateStoryClearNum1.msgCode = 0x007f;
 updateStoryClearNum1.msgLen = 0x0010;
 
 export function updateStoryClearNum1(
@@ -16,7 +15,7 @@ export function updateStoryClearNum1(
   };
 }
 
-updateStoryClearNum2.msgCode = 0x013d as RequestCode;
+updateStoryClearNum2.msgCode = 0x013d;
 updateStoryClearNum2.msgLen = 0x0010;
 
 export function updateStoryClearNum2(
diff --git a/src/idz/decoder/updateTeamLeader.ts b/src/idz/decoder/updateTeamLeader.ts
index ca247b4..fb2b0e2 100644
--- a/src/idz/decoder/updateTeamLeader.ts
+++ b/src/idz/decoder/updateTeamLeader.ts
@@ -1,10 +1,9 @@
-import { RequestCode } from "./_defs";
 import { ExtId } from "../model/base";
 import { Team } from "../model/team";
 import { UpdateTeamLeaderRequest } from "../request/updateTeamLeader";
 import { AimeId } from "../../model";
 
-updateTeamLeader.msgCode = 0x008a as RequestCode;
+updateTeamLeader.msgCode = 0x008a;
 updateTeamLeader.msgLen = 0x0020;
 
 export function updateTeamLeader(buf: Buffer): UpdateTeamLeaderRequest {
diff --git a/src/idz/decoder/updateTeamMember.ts b/src/idz/decoder/updateTeamMember.ts
index 04f9e23..62d1316 100644
--- a/src/idz/decoder/updateTeamMember.ts
+++ b/src/idz/decoder/updateTeamMember.ts
@@ -1,10 +1,9 @@
-import { RequestCode } from "./_defs";
 import { ExtId } from "../model/base";
 import { Team } from "../model/team";
 import { UpdateTeamMemberRequest } from "../request/updateTeamMember";
 import { AimeId } from "../../model";
 
-updateTeamMember.msgCode = 0x0073 as RequestCode;
+updateTeamMember.msgCode = 0x0073;
 updateTeamMember.msgLen = 0x0010;
 
 export function updateTeamMember(buf: Buffer): UpdateTeamMemberRequest {
diff --git a/src/idz/decoder/updateTeamPoints.ts b/src/idz/decoder/updateTeamPoints.ts
index d59fc02..21345fe 100644
--- a/src/idz/decoder/updateTeamPoints.ts
+++ b/src/idz/decoder/updateTeamPoints.ts
@@ -1,7 +1,6 @@
-import { RequestCode } from "./_defs";
 import { UpdateTeamPointsRequest } from "../request/updateTeamPoints";
 
-updateTeamPoints.msgCode = 0x0081 as RequestCode;
+updateTeamPoints.msgCode = 0x0081;
 updateTeamPoints.msgLen = 0x0010;
 
 export function updateTeamPoints(buf: Buffer): UpdateTeamPointsRequest {
diff --git a/src/idz/decoder/updateUiReport.ts b/src/idz/decoder/updateUiReport.ts
index 85a94ed..4403187 100644
--- a/src/idz/decoder/updateUiReport.ts
+++ b/src/idz/decoder/updateUiReport.ts
@@ -1,7 +1,6 @@
-import { RequestCode } from "./_defs";
 import { UpdateUiReportRequest } from "../request/updateUiReport";
 
-updateUiReport.msgCode = 0x0084 as RequestCode;
+updateUiReport.msgCode = 0x0084;
 updateUiReport.msgLen = 0x0410;
 
 export function updateUiReport(buf: Buffer): UpdateUiReportRequest {
diff --git a/src/idz/decoder/updateUserLog.ts b/src/idz/decoder/updateUserLog.ts
index 3722a7a..32dcea5 100644
--- a/src/idz/decoder/updateUserLog.ts
+++ b/src/idz/decoder/updateUserLog.ts
@@ -1,7 +1,6 @@
-import { RequestCode } from "./_defs";
 import { UpdateUserLogRequest } from "../request/updateUserLog";
 
-updateUserLog.msgCode = 0x00bd as RequestCode;
+updateUserLog.msgCode = 0x00bd;
 updateUserLog.msgLen = 0x0050;
 
 export function updateUserLog(buf: Buffer): UpdateUserLogRequest {