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 23aa2e526804..9bed60ee16aa 100644
--- a/modules/openapi-generator/src/main/resources/typescript-fetch/apis.mustache
+++ b/modules/openapi-generator/src/main/resources/typescript-fetch/apis.mustache
@@ -351,10 +351,24 @@ export class {{classname}} extends runtime.BaseAPI {
      {{/isDeprecated}}
      */
     {{^useSingleRequestParameter}}
-    async {{nickname}}({{#allParams}}{{paramName}}{{^required}}?{{/required}}: {{#isEnum}}{{{datatypeWithEnum}}}{{/isEnum}}{{^isEnum}}{{{dataType}}}{{#isNullable}} | null{{/isNullable}}{{/isEnum}}, {{/allParams}}initOverrides?: RequestInit | runtime.InitOverrideFunction): Promise<{{{returnType}}}{{^returnType}}void{{/returnType}}> {
+    async {{nickname}}({{#allParams}}{{paramName}}{{^required}}?{{/required}}: {{#isEnum}}{{{datatypeWithEnum}}}{{/isEnum}}{{^isEnum}}{{{dataType}}}{{#isNullable}} | null{{/isNullable}}{{/isEnum}}, {{/allParams}}initOverrides?: RequestInit | runtime.InitOverrideFunction): Promise<{{{returnType}}}{{#returnType}}{{#isResponseOptional}} | null | undefined {{/isResponseOptional}}{{/returnType}}{{^returnType}}void{{/returnType}}> {
         {{#returnType}}
         const response = await this.{{nickname}}Raw({{#allParams.0}}{ {{#allParams}}{{paramName}}: {{paramName}}{{^-last}}, {{/-last}}{{/allParams}} }, {{/allParams.0}}initOverrides);
+        {{#isResponseOptional}}
+        switch (response.raw.status) {
+            {{#responses}}
+            {{#is2xx}}
+            case {{code}}:
+                return {{#dataType}}await response.value(){{/dataType}}{{^dataType}}null{{/dataType}};
+            {{/is2xx}}
+            {{/responses}}
+            default:
+                return await response.value();
+        }
+        {{/isResponseOptional}}
+        {{^isResponseOptional}}
         return await response.value();
+        {{/isResponseOptional}}
         {{/returnType}}
         {{^returnType}}
         await this.{{nickname}}Raw({{#allParams.0}}{ {{#allParams}}{{paramName}}: {{paramName}}{{^-last}}, {{/-last}}{{/allParams}} }, {{/allParams.0}}initOverrides);
@@ -362,10 +376,24 @@ export class {{classname}} extends runtime.BaseAPI {
     }
     {{/useSingleRequestParameter}}
     {{#useSingleRequestParameter}}
-    async {{nickname}}({{#allParams.0}}requestParameters: {{#prefixParameterInterfaces}}{{classname}}{{/prefixParameterInterfaces}}{{operationIdCamelCase}}Request{{^hasRequiredParams}} = {}{{/hasRequiredParams}}, {{/allParams.0}}initOverrides?: RequestInit | runtime.InitOverrideFunction): Promise<{{{returnType}}}{{^returnType}}void{{/returnType}}> {
+    async {{nickname}}({{#allParams.0}}requestParameters: {{#prefixParameterInterfaces}}{{classname}}{{/prefixParameterInterfaces}}{{operationIdCamelCase}}Request{{^hasRequiredParams}} = {}{{/hasRequiredParams}}, {{/allParams.0}}initOverrides?: RequestInit | runtime.InitOverrideFunction): Promise<{{{returnType}}}{{#returnType}}{{#isResponseOptional}} | null | undefined {{/isResponseOptional}}{{/returnType}}{{^returnType}}void{{/returnType}}> {
         {{#returnType}}
         const response = await this.{{nickname}}Raw({{#allParams.0}}requestParameters, {{/allParams.0}}initOverrides);
+        {{#isResponseOptional}}
+        switch (response.raw.status) {
+            {{#responses}}
+            {{#is2xx}}
+            case {{code}}:
+                return {{#dataType}}await response.value(){{/dataType}}{{^dataType}}null{{/dataType}};
+            {{/is2xx}}
+            {{/responses}}
+            default:
+                return await response.value();
+        }
+        {{/isResponseOptional}}
+        {{^isResponseOptional}}
         return await response.value();
+        {{/isResponseOptional}}
         {{/returnType}}
         {{^returnType}}
         await this.{{nickname}}Raw({{#allParams.0}}requestParameters, {{/allParams.0}}initOverrides);