diff --git a/modules/openapi-generator/src/main/resources/typescript-fetch/modelEnum.mustache b/modules/openapi-generator/src/main/resources/typescript-fetch/modelEnum.mustache
index 20f21ef5c9f1..5bab7a5a98c2 100644
--- a/modules/openapi-generator/src/main/resources/typescript-fetch/modelEnum.mustache
+++ b/modules/openapi-generator/src/main/resources/typescript-fetch/modelEnum.mustache
@@ -3,7 +3,7 @@
 export function instanceOf{{classname}}(value: any): boolean {
     for (const key in {{classname}}) {
         if (Object.prototype.hasOwnProperty.call({{classname}}, key)) {
-            if (({{classname}} as Record<string, {{classname}}>)[key] === value) {
+            if ({{classname}}[key as keyof typeof {{classname}}] === value) {
                 return true;
             }
         }
diff --git a/samples/client/petstore/typescript-fetch/builds/default-v3.0/models/EnumClass.ts b/samples/client/petstore/typescript-fetch/builds/default-v3.0/models/EnumClass.ts
index 3233ca6c9494..c58c82e92569 100644
--- a/samples/client/petstore/typescript-fetch/builds/default-v3.0/models/EnumClass.ts
+++ b/samples/client/petstore/typescript-fetch/builds/default-v3.0/models/EnumClass.ts
@@ -28,7 +28,7 @@ export type EnumClass = typeof EnumClass[keyof typeof EnumClass];
 export function instanceOfEnumClass(value: any): boolean {
     for (const key in EnumClass) {
         if (Object.prototype.hasOwnProperty.call(EnumClass, key)) {
-            if ((EnumClass as Record<string, EnumClass>)[key] === value) {
+            if (EnumClass[key as keyof typeof EnumClass] === value) {
                 return true;
             }
         }
diff --git a/samples/client/petstore/typescript-fetch/builds/default-v3.0/models/OuterEnum.ts b/samples/client/petstore/typescript-fetch/builds/default-v3.0/models/OuterEnum.ts
index b4427d5dad3d..2c304d574003 100644
--- a/samples/client/petstore/typescript-fetch/builds/default-v3.0/models/OuterEnum.ts
+++ b/samples/client/petstore/typescript-fetch/builds/default-v3.0/models/OuterEnum.ts
@@ -28,7 +28,7 @@ export type OuterEnum = typeof OuterEnum[keyof typeof OuterEnum];
 export function instanceOfOuterEnum(value: any): boolean {
     for (const key in OuterEnum) {
         if (Object.prototype.hasOwnProperty.call(OuterEnum, key)) {
-            if ((OuterEnum as Record<string, OuterEnum>)[key] === value) {
+            if (OuterEnum[key as keyof typeof OuterEnum] === value) {
                 return true;
             }
         }
diff --git a/samples/client/petstore/typescript-fetch/builds/default-v3.0/models/OuterEnumDefaultValue.ts b/samples/client/petstore/typescript-fetch/builds/default-v3.0/models/OuterEnumDefaultValue.ts
index 5c44e1853716..c5aabe1ad685 100644
--- a/samples/client/petstore/typescript-fetch/builds/default-v3.0/models/OuterEnumDefaultValue.ts
+++ b/samples/client/petstore/typescript-fetch/builds/default-v3.0/models/OuterEnumDefaultValue.ts
@@ -28,7 +28,7 @@ export type OuterEnumDefaultValue = typeof OuterEnumDefaultValue[keyof typeof Ou
 export function instanceOfOuterEnumDefaultValue(value: any): boolean {
     for (const key in OuterEnumDefaultValue) {
         if (Object.prototype.hasOwnProperty.call(OuterEnumDefaultValue, key)) {
-            if ((OuterEnumDefaultValue as Record<string, OuterEnumDefaultValue>)[key] === value) {
+            if (OuterEnumDefaultValue[key as keyof typeof OuterEnumDefaultValue] === value) {
                 return true;
             }
         }
diff --git a/samples/client/petstore/typescript-fetch/builds/default-v3.0/models/OuterEnumInteger.ts b/samples/client/petstore/typescript-fetch/builds/default-v3.0/models/OuterEnumInteger.ts
index 33609e9b0f3d..cb5a0a251509 100644
--- a/samples/client/petstore/typescript-fetch/builds/default-v3.0/models/OuterEnumInteger.ts
+++ b/samples/client/petstore/typescript-fetch/builds/default-v3.0/models/OuterEnumInteger.ts
@@ -28,7 +28,7 @@ export type OuterEnumInteger = typeof OuterEnumInteger[keyof typeof OuterEnumInt
 export function instanceOfOuterEnumInteger(value: any): boolean {
     for (const key in OuterEnumInteger) {
         if (Object.prototype.hasOwnProperty.call(OuterEnumInteger, key)) {
-            if ((OuterEnumInteger as Record<string, OuterEnumInteger>)[key] === value) {
+            if (OuterEnumInteger[key as keyof typeof OuterEnumInteger] === value) {
                 return true;
             }
         }
diff --git a/samples/client/petstore/typescript-fetch/builds/default-v3.0/models/OuterEnumIntegerDefaultValue.ts b/samples/client/petstore/typescript-fetch/builds/default-v3.0/models/OuterEnumIntegerDefaultValue.ts
index 08927e2f8f80..1e9b73ce4956 100644
--- a/samples/client/petstore/typescript-fetch/builds/default-v3.0/models/OuterEnumIntegerDefaultValue.ts
+++ b/samples/client/petstore/typescript-fetch/builds/default-v3.0/models/OuterEnumIntegerDefaultValue.ts
@@ -28,7 +28,7 @@ export type OuterEnumIntegerDefaultValue = typeof OuterEnumIntegerDefaultValue[k
 export function instanceOfOuterEnumIntegerDefaultValue(value: any): boolean {
     for (const key in OuterEnumIntegerDefaultValue) {
         if (Object.prototype.hasOwnProperty.call(OuterEnumIntegerDefaultValue, key)) {
-            if ((OuterEnumIntegerDefaultValue as Record<string, OuterEnumIntegerDefaultValue>)[key] === value) {
+            if (OuterEnumIntegerDefaultValue[key as keyof typeof OuterEnumIntegerDefaultValue] === value) {
                 return true;
             }
         }
diff --git a/samples/client/petstore/typescript-fetch/builds/default-v3.0/models/SingleRefType.ts b/samples/client/petstore/typescript-fetch/builds/default-v3.0/models/SingleRefType.ts
index 8daaecf3c495..260be835d982 100644
--- a/samples/client/petstore/typescript-fetch/builds/default-v3.0/models/SingleRefType.ts
+++ b/samples/client/petstore/typescript-fetch/builds/default-v3.0/models/SingleRefType.ts
@@ -27,7 +27,7 @@ export type SingleRefType = typeof SingleRefType[keyof typeof SingleRefType];
 export function instanceOfSingleRefType(value: any): boolean {
     for (const key in SingleRefType) {
         if (Object.prototype.hasOwnProperty.call(SingleRefType, key)) {
-            if ((SingleRefType as Record<string, SingleRefType>)[key] === value) {
+            if (SingleRefType[key as keyof typeof SingleRefType] === value) {
                 return true;
             }
         }
diff --git a/samples/client/petstore/typescript-fetch/builds/enum/models/NumberEnum.ts b/samples/client/petstore/typescript-fetch/builds/enum/models/NumberEnum.ts
index 225a39078447..1684281cc9ad 100644
--- a/samples/client/petstore/typescript-fetch/builds/enum/models/NumberEnum.ts
+++ b/samples/client/petstore/typescript-fetch/builds/enum/models/NumberEnum.ts
@@ -28,7 +28,7 @@ export type NumberEnum = typeof NumberEnum[keyof typeof NumberEnum];
 export function instanceOfNumberEnum(value: any): boolean {
     for (const key in NumberEnum) {
         if (Object.prototype.hasOwnProperty.call(NumberEnum, key)) {
-            if ((NumberEnum as Record<string, NumberEnum>)[key] === value) {
+            if (NumberEnum[key as keyof typeof NumberEnum] === value) {
                 return true;
             }
         }
diff --git a/samples/client/petstore/typescript-fetch/builds/enum/models/StringEnum.ts b/samples/client/petstore/typescript-fetch/builds/enum/models/StringEnum.ts
index 1f7477bf1687..1b1a1f1e5ae8 100644
--- a/samples/client/petstore/typescript-fetch/builds/enum/models/StringEnum.ts
+++ b/samples/client/petstore/typescript-fetch/builds/enum/models/StringEnum.ts
@@ -28,7 +28,7 @@ export type StringEnum = typeof StringEnum[keyof typeof StringEnum];
 export function instanceOfStringEnum(value: any): boolean {
     for (const key in StringEnum) {
         if (Object.prototype.hasOwnProperty.call(StringEnum, key)) {
-            if ((StringEnum as Record<string, StringEnum>)[key] === value) {
+            if (StringEnum[key as keyof typeof StringEnum] === value) {
                 return true;
             }
         }
diff --git a/samples/client/petstore/typescript-fetch/builds/sagas-and-records/src/models/BehaviorType.ts b/samples/client/petstore/typescript-fetch/builds/sagas-and-records/src/models/BehaviorType.ts
index a16d3f8c2656..6792815d839d 100644
--- a/samples/client/petstore/typescript-fetch/builds/sagas-and-records/src/models/BehaviorType.ts
+++ b/samples/client/petstore/typescript-fetch/builds/sagas-and-records/src/models/BehaviorType.ts
@@ -28,7 +28,7 @@ export type BehaviorType = typeof BehaviorType[keyof typeof BehaviorType];
 export function instanceOfBehaviorType(value: any): boolean {
     for (const key in BehaviorType) {
         if (Object.prototype.hasOwnProperty.call(BehaviorType, key)) {
-            if ((BehaviorType as Record<string, BehaviorType>)[key] === value) {
+            if (BehaviorType[key as keyof typeof BehaviorType] === value) {
                 return true;
             }
         }
diff --git a/samples/client/petstore/typescript-fetch/builds/sagas-and-records/src/models/DeploymentRequestStatus.ts b/samples/client/petstore/typescript-fetch/builds/sagas-and-records/src/models/DeploymentRequestStatus.ts
index 0a84d2dce814..5ae82e7f2ef4 100644
--- a/samples/client/petstore/typescript-fetch/builds/sagas-and-records/src/models/DeploymentRequestStatus.ts
+++ b/samples/client/petstore/typescript-fetch/builds/sagas-and-records/src/models/DeploymentRequestStatus.ts
@@ -37,7 +37,7 @@ export type DeploymentRequestStatus = typeof DeploymentRequestStatus[keyof typeo
 export function instanceOfDeploymentRequestStatus(value: any): boolean {
     for (const key in DeploymentRequestStatus) {
         if (Object.prototype.hasOwnProperty.call(DeploymentRequestStatus, key)) {
-            if ((DeploymentRequestStatus as Record<string, DeploymentRequestStatus>)[key] === value) {
+            if (DeploymentRequestStatus[key as keyof typeof DeploymentRequestStatus] === value) {
                 return true;
             }
         }
diff --git a/samples/client/petstore/typescript-fetch/builds/sagas-and-records/src/models/ErrorCode.ts b/samples/client/petstore/typescript-fetch/builds/sagas-and-records/src/models/ErrorCode.ts
index 669c957006c3..7b85047567d8 100644
--- a/samples/client/petstore/typescript-fetch/builds/sagas-and-records/src/models/ErrorCode.ts
+++ b/samples/client/petstore/typescript-fetch/builds/sagas-and-records/src/models/ErrorCode.ts
@@ -43,7 +43,7 @@ export type ErrorCode = typeof ErrorCode[keyof typeof ErrorCode];
 export function instanceOfErrorCode(value: any): boolean {
     for (const key in ErrorCode) {
         if (Object.prototype.hasOwnProperty.call(ErrorCode, key)) {
-            if ((ErrorCode as Record<string, ErrorCode>)[key] === value) {
+            if (ErrorCode[key as keyof typeof ErrorCode] === value) {
                 return true;
             }
         }
diff --git a/samples/client/petstore/typescript-fetch/builds/sagas-and-records/src/models/PetPartType.ts b/samples/client/petstore/typescript-fetch/builds/sagas-and-records/src/models/PetPartType.ts
index d03752c43ddd..0529649ea2df 100644
--- a/samples/client/petstore/typescript-fetch/builds/sagas-and-records/src/models/PetPartType.ts
+++ b/samples/client/petstore/typescript-fetch/builds/sagas-and-records/src/models/PetPartType.ts
@@ -28,7 +28,7 @@ export type PetPartType = typeof PetPartType[keyof typeof PetPartType];
 export function instanceOfPetPartType(value: any): boolean {
     for (const key in PetPartType) {
         if (Object.prototype.hasOwnProperty.call(PetPartType, key)) {
-            if ((PetPartType as Record<string, PetPartType>)[key] === value) {
+            if (PetPartType[key as keyof typeof PetPartType] === value) {
                 return true;
             }
         }
diff --git a/samples/client/petstore/typescript-fetch/builds/sagas-and-records/src/models/WarningCode.ts b/samples/client/petstore/typescript-fetch/builds/sagas-and-records/src/models/WarningCode.ts
index 3d73bec13539..2ebc7a17f0a1 100644
--- a/samples/client/petstore/typescript-fetch/builds/sagas-and-records/src/models/WarningCode.ts
+++ b/samples/client/petstore/typescript-fetch/builds/sagas-and-records/src/models/WarningCode.ts
@@ -28,7 +28,7 @@ export type WarningCode = typeof WarningCode[keyof typeof WarningCode];
 export function instanceOfWarningCode(value: any): boolean {
     for (const key in WarningCode) {
         if (Object.prototype.hasOwnProperty.call(WarningCode, key)) {
-            if ((WarningCode as Record<string, WarningCode>)[key] === value) {
+            if (WarningCode[key as keyof typeof WarningCode] === value) {
                 return true;
             }
         }
diff --git a/samples/client/petstore/typescript-fetch/builds/snakecase-discriminator/models/EnumClass.ts b/samples/client/petstore/typescript-fetch/builds/snakecase-discriminator/models/EnumClass.ts
index 3233ca6c9494..c58c82e92569 100644
--- a/samples/client/petstore/typescript-fetch/builds/snakecase-discriminator/models/EnumClass.ts
+++ b/samples/client/petstore/typescript-fetch/builds/snakecase-discriminator/models/EnumClass.ts
@@ -28,7 +28,7 @@ export type EnumClass = typeof EnumClass[keyof typeof EnumClass];
 export function instanceOfEnumClass(value: any): boolean {
     for (const key in EnumClass) {
         if (Object.prototype.hasOwnProperty.call(EnumClass, key)) {
-            if ((EnumClass as Record<string, EnumClass>)[key] === value) {
+            if (EnumClass[key as keyof typeof EnumClass] === value) {
                 return true;
             }
         }
diff --git a/samples/client/petstore/typescript-fetch/builds/snakecase-discriminator/models/OuterEnum.ts b/samples/client/petstore/typescript-fetch/builds/snakecase-discriminator/models/OuterEnum.ts
index b4427d5dad3d..2c304d574003 100644
--- a/samples/client/petstore/typescript-fetch/builds/snakecase-discriminator/models/OuterEnum.ts
+++ b/samples/client/petstore/typescript-fetch/builds/snakecase-discriminator/models/OuterEnum.ts
@@ -28,7 +28,7 @@ export type OuterEnum = typeof OuterEnum[keyof typeof OuterEnum];
 export function instanceOfOuterEnum(value: any): boolean {
     for (const key in OuterEnum) {
         if (Object.prototype.hasOwnProperty.call(OuterEnum, key)) {
-            if ((OuterEnum as Record<string, OuterEnum>)[key] === value) {
+            if (OuterEnum[key as keyof typeof OuterEnum] === value) {
                 return true;
             }
         }
diff --git a/samples/client/petstore/typescript-fetch/builds/snakecase-discriminator/models/OuterEnumDefaultValue.ts b/samples/client/petstore/typescript-fetch/builds/snakecase-discriminator/models/OuterEnumDefaultValue.ts
index 5c44e1853716..c5aabe1ad685 100644
--- a/samples/client/petstore/typescript-fetch/builds/snakecase-discriminator/models/OuterEnumDefaultValue.ts
+++ b/samples/client/petstore/typescript-fetch/builds/snakecase-discriminator/models/OuterEnumDefaultValue.ts
@@ -28,7 +28,7 @@ export type OuterEnumDefaultValue = typeof OuterEnumDefaultValue[keyof typeof Ou
 export function instanceOfOuterEnumDefaultValue(value: any): boolean {
     for (const key in OuterEnumDefaultValue) {
         if (Object.prototype.hasOwnProperty.call(OuterEnumDefaultValue, key)) {
-            if ((OuterEnumDefaultValue as Record<string, OuterEnumDefaultValue>)[key] === value) {
+            if (OuterEnumDefaultValue[key as keyof typeof OuterEnumDefaultValue] === value) {
                 return true;
             }
         }
diff --git a/samples/client/petstore/typescript-fetch/builds/snakecase-discriminator/models/OuterEnumInteger.ts b/samples/client/petstore/typescript-fetch/builds/snakecase-discriminator/models/OuterEnumInteger.ts
index 33609e9b0f3d..cb5a0a251509 100644
--- a/samples/client/petstore/typescript-fetch/builds/snakecase-discriminator/models/OuterEnumInteger.ts
+++ b/samples/client/petstore/typescript-fetch/builds/snakecase-discriminator/models/OuterEnumInteger.ts
@@ -28,7 +28,7 @@ export type OuterEnumInteger = typeof OuterEnumInteger[keyof typeof OuterEnumInt
 export function instanceOfOuterEnumInteger(value: any): boolean {
     for (const key in OuterEnumInteger) {
         if (Object.prototype.hasOwnProperty.call(OuterEnumInteger, key)) {
-            if ((OuterEnumInteger as Record<string, OuterEnumInteger>)[key] === value) {
+            if (OuterEnumInteger[key as keyof typeof OuterEnumInteger] === value) {
                 return true;
             }
         }
diff --git a/samples/client/petstore/typescript-fetch/builds/snakecase-discriminator/models/OuterEnumIntegerDefaultValue.ts b/samples/client/petstore/typescript-fetch/builds/snakecase-discriminator/models/OuterEnumIntegerDefaultValue.ts
index 08927e2f8f80..1e9b73ce4956 100644
--- a/samples/client/petstore/typescript-fetch/builds/snakecase-discriminator/models/OuterEnumIntegerDefaultValue.ts
+++ b/samples/client/petstore/typescript-fetch/builds/snakecase-discriminator/models/OuterEnumIntegerDefaultValue.ts
@@ -28,7 +28,7 @@ export type OuterEnumIntegerDefaultValue = typeof OuterEnumIntegerDefaultValue[k
 export function instanceOfOuterEnumIntegerDefaultValue(value: any): boolean {
     for (const key in OuterEnumIntegerDefaultValue) {
         if (Object.prototype.hasOwnProperty.call(OuterEnumIntegerDefaultValue, key)) {
-            if ((OuterEnumIntegerDefaultValue as Record<string, OuterEnumIntegerDefaultValue>)[key] === value) {
+            if (OuterEnumIntegerDefaultValue[key as keyof typeof OuterEnumIntegerDefaultValue] === value) {
                 return true;
             }
         }
diff --git a/samples/client/petstore/typescript-fetch/builds/snakecase-discriminator/models/SingleRefType.ts b/samples/client/petstore/typescript-fetch/builds/snakecase-discriminator/models/SingleRefType.ts
index 8daaecf3c495..260be835d982 100644
--- a/samples/client/petstore/typescript-fetch/builds/snakecase-discriminator/models/SingleRefType.ts
+++ b/samples/client/petstore/typescript-fetch/builds/snakecase-discriminator/models/SingleRefType.ts
@@ -27,7 +27,7 @@ export type SingleRefType = typeof SingleRefType[keyof typeof SingleRefType];
 export function instanceOfSingleRefType(value: any): boolean {
     for (const key in SingleRefType) {
         if (Object.prototype.hasOwnProperty.call(SingleRefType, key)) {
-            if ((SingleRefType as Record<string, SingleRefType>)[key] === value) {
+            if (SingleRefType[key as keyof typeof SingleRefType] === value) {
                 return true;
             }
         }
diff --git a/samples/client/petstore/typescript-fetch/builds/with-string-enums/models/NumberEnum.ts b/samples/client/petstore/typescript-fetch/builds/with-string-enums/models/NumberEnum.ts
index 18a96213d14d..2181967c9a69 100644
--- a/samples/client/petstore/typescript-fetch/builds/with-string-enums/models/NumberEnum.ts
+++ b/samples/client/petstore/typescript-fetch/builds/with-string-enums/models/NumberEnum.ts
@@ -27,7 +27,7 @@ export enum NumberEnum {
 export function instanceOfNumberEnum(value: any): boolean {
     for (const key in NumberEnum) {
         if (Object.prototype.hasOwnProperty.call(NumberEnum, key)) {
-            if ((NumberEnum as Record<string, NumberEnum>)[key] === value) {
+            if (NumberEnum[key as keyof typeof NumberEnum] === value) {
                 return true;
             }
         }
diff --git a/samples/client/petstore/typescript-fetch/builds/with-string-enums/models/StringEnum.ts b/samples/client/petstore/typescript-fetch/builds/with-string-enums/models/StringEnum.ts
index 43acb9cc477b..bcb11c3d400b 100644
--- a/samples/client/petstore/typescript-fetch/builds/with-string-enums/models/StringEnum.ts
+++ b/samples/client/petstore/typescript-fetch/builds/with-string-enums/models/StringEnum.ts
@@ -27,7 +27,7 @@ export enum StringEnum {
 export function instanceOfStringEnum(value: any): boolean {
     for (const key in StringEnum) {
         if (Object.prototype.hasOwnProperty.call(StringEnum, key)) {
-            if ((StringEnum as Record<string, StringEnum>)[key] === value) {
+            if (StringEnum[key as keyof typeof StringEnum] === value) {
                 return true;
             }
         }