diff --git a/modules/openapi-generator/src/main/resources/typescript-fetch/modelOneOf.mustache b/modules/openapi-generator/src/main/resources/typescript-fetch/modelOneOf.mustache
index e5b54a1d852b..7d5c01878949 100644
--- a/modules/openapi-generator/src/main/resources/typescript-fetch/modelOneOf.mustache
+++ b/modules/openapi-generator/src/main/resources/typescript-fetch/modelOneOf.mustache
@@ -142,7 +142,7 @@ export function {{classname}}ToJSONTyped(value?: {{classname}} | null, ignoreDis
             return Object.assign({}, {{modelName}}ToJSON(value), { {{discriminator.propertyName}}: '{{mappingName}}' } as const);
 {{/discriminator.mappedModels}}
         default:
-            return json;
+            return value;
     }
 {{/discriminator}}
 {{^discriminator}}
diff --git a/samples/client/petstore/typescript-fetch/builds/oneOf/models/TestDiscriminatorResponse.ts b/samples/client/petstore/typescript-fetch/builds/oneOf/models/TestDiscriminatorResponse.ts
index c6be9b26c5e3..0596cafad7e1 100644
--- a/samples/client/petstore/typescript-fetch/builds/oneOf/models/TestDiscriminatorResponse.ts
+++ b/samples/client/petstore/typescript-fetch/builds/oneOf/models/TestDiscriminatorResponse.ts
@@ -66,7 +66,7 @@ export function TestDiscriminatorResponseToJSONTyped(value?: TestDiscriminatorRe
         case 'optionTwo':
             return Object.assign({}, OptionTwoToJSON(value), { discriminatorField: 'optionTwo' } as const);
         default:
-            return json;
+            return value;
     }
 }