diff --git a/modules/openapi-generator/src/main/resources/typescript-fetch/apis.mustache b/modules/openapi-generator/src/main/resources/typescript-fetch/apis.mustache
index 5149d534b8c0..73504161a163 100644
--- a/modules/openapi-generator/src/main/resources/typescript-fetch/apis.mustache
+++ b/modules/openapi-generator/src/main/resources/typescript-fetch/apis.mustache
@@ -232,7 +232,7 @@ export class {{classname}} extends runtime.BaseAPI {
         return new runtime.JSONApiResponse<any>(response);
         {{/isListContainer}}
         {{#returnSimpleType}}
-        return new runtime.TextApiResponse(response);
+        return new runtime.TextApiResponse(response) as any;
         {{/returnSimpleType}}
         {{/returnTypeIsPrimitive}}
         {{^returnTypeIsPrimitive}}
diff --git a/samples/client/petstore/typescript-fetch/builds/default/src/apis/UserApi.ts b/samples/client/petstore/typescript-fetch/builds/default/src/apis/UserApi.ts
index 4126b817ee94..52d6f3d2e3d2 100644
--- a/samples/client/petstore/typescript-fetch/builds/default/src/apis/UserApi.ts
+++ b/samples/client/petstore/typescript-fetch/builds/default/src/apis/UserApi.ts
@@ -244,7 +244,7 @@ export class UserApi extends runtime.BaseAPI {
             query: queryParameters,
         });
 
-        return new runtime.TextApiResponse(response);
+        return new runtime.TextApiResponse(response) as any;
     }
 
     /**
diff --git a/samples/client/petstore/typescript-fetch/builds/es6-target/src/apis/UserApi.ts b/samples/client/petstore/typescript-fetch/builds/es6-target/src/apis/UserApi.ts
index 4126b817ee94..52d6f3d2e3d2 100644
--- a/samples/client/petstore/typescript-fetch/builds/es6-target/src/apis/UserApi.ts
+++ b/samples/client/petstore/typescript-fetch/builds/es6-target/src/apis/UserApi.ts
@@ -244,7 +244,7 @@ export class UserApi extends runtime.BaseAPI {
             query: queryParameters,
         });
 
-        return new runtime.TextApiResponse(response);
+        return new runtime.TextApiResponse(response) as any;
     }
 
     /**
diff --git a/samples/client/petstore/typescript-fetch/builds/multiple-parameters/src/apis/UserApi.ts b/samples/client/petstore/typescript-fetch/builds/multiple-parameters/src/apis/UserApi.ts
index ce75bed4fd16..008d458aca19 100644
--- a/samples/client/petstore/typescript-fetch/builds/multiple-parameters/src/apis/UserApi.ts
+++ b/samples/client/petstore/typescript-fetch/builds/multiple-parameters/src/apis/UserApi.ts
@@ -244,7 +244,7 @@ export class UserApi extends runtime.BaseAPI {
             query: queryParameters,
         });
 
-        return new runtime.TextApiResponse(response);
+        return new runtime.TextApiResponse(response) as any;
     }
 
     /**
diff --git a/samples/client/petstore/typescript-fetch/builds/prefix-parameter-interfaces/src/apis/UserApi.ts b/samples/client/petstore/typescript-fetch/builds/prefix-parameter-interfaces/src/apis/UserApi.ts
index f28cd54fc893..7738fe82ea68 100644
--- a/samples/client/petstore/typescript-fetch/builds/prefix-parameter-interfaces/src/apis/UserApi.ts
+++ b/samples/client/petstore/typescript-fetch/builds/prefix-parameter-interfaces/src/apis/UserApi.ts
@@ -244,7 +244,7 @@ export class UserApi extends runtime.BaseAPI {
             query: queryParameters,
         });
 
-        return new runtime.TextApiResponse(response);
+        return new runtime.TextApiResponse(response) as any;
     }
 
     /**
diff --git a/samples/client/petstore/typescript-fetch/builds/typescript-three-plus/src/apis/UserApi.ts b/samples/client/petstore/typescript-fetch/builds/typescript-three-plus/src/apis/UserApi.ts
index 4126b817ee94..52d6f3d2e3d2 100644
--- a/samples/client/petstore/typescript-fetch/builds/typescript-three-plus/src/apis/UserApi.ts
+++ b/samples/client/petstore/typescript-fetch/builds/typescript-three-plus/src/apis/UserApi.ts
@@ -244,7 +244,7 @@ export class UserApi extends runtime.BaseAPI {
             query: queryParameters,
         });
 
-        return new runtime.TextApiResponse(response);
+        return new runtime.TextApiResponse(response) as any;
     }
 
     /**
diff --git a/samples/client/petstore/typescript-fetch/builds/with-interfaces/src/apis/UserApi.ts b/samples/client/petstore/typescript-fetch/builds/with-interfaces/src/apis/UserApi.ts
index 4126b817ee94..52d6f3d2e3d2 100644
--- a/samples/client/petstore/typescript-fetch/builds/with-interfaces/src/apis/UserApi.ts
+++ b/samples/client/petstore/typescript-fetch/builds/with-interfaces/src/apis/UserApi.ts
@@ -244,7 +244,7 @@ export class UserApi extends runtime.BaseAPI {
             query: queryParameters,
         });
 
-        return new runtime.TextApiResponse(response);
+        return new runtime.TextApiResponse(response) as any;
     }
 
     /**
diff --git a/samples/client/petstore/typescript-fetch/builds/with-npm-version/src/apis/UserApi.ts b/samples/client/petstore/typescript-fetch/builds/with-npm-version/src/apis/UserApi.ts
index 4126b817ee94..52d6f3d2e3d2 100644
--- a/samples/client/petstore/typescript-fetch/builds/with-npm-version/src/apis/UserApi.ts
+++ b/samples/client/petstore/typescript-fetch/builds/with-npm-version/src/apis/UserApi.ts
@@ -244,7 +244,7 @@ export class UserApi extends runtime.BaseAPI {
             query: queryParameters,
         });
 
-        return new runtime.TextApiResponse(response);
+        return new runtime.TextApiResponse(response) as any;
     }
 
     /**