diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptFetchClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptFetchClientCodegen.java
index 8924e3b0b62f..0d47cdcd7ac6 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptFetchClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptFetchClientCodegen.java
@@ -85,9 +85,6 @@ public TypeScriptFetchClientCodegen() {
 
         this.addExtraReservedWords();
 
-        typeMapping.put("date", "Date");
-        typeMapping.put("DateTime", "Date");
-
         supportModelPropertyNaming(CodegenConstants.MODEL_PROPERTY_NAMING_TYPE.camelCase);
         this.cliOptions.add(new CliOption(NPM_REPOSITORY, "Use this property to set an url your private npmRepo in the package.json"));
         this.cliOptions.add(new CliOption(WITH_INTERFACES, "Setting this property to true will generate interfaces next to the default class implementations.", SchemaTypeUtil.BOOLEAN_TYPE).defaultValue(Boolean.FALSE.toString()));
@@ -231,6 +228,8 @@ public void processOpts() {
 
         if (!withoutRuntimeChecks) {
             this.modelTemplateFiles.put("models.mustache", ".ts");
+            typeMapping.put("date", "Date");
+            typeMapping.put("DateTime", "Date");
         }
 
         if (additionalProperties.containsKey(SAGAS_AND_RECORDS)) {
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/typescript/fetch/TypeScriptFetchModelTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/typescript/fetch/TypeScriptFetchModelTest.java
index 8b43b94a8ce9..9bc7c709487a 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/typescript/fetch/TypeScriptFetchModelTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/typescript/fetch/TypeScriptFetchModelTest.java
@@ -61,6 +61,7 @@ public void simpleModelTest() {
                 .addRequiredItem("name");
 
         final DefaultCodegen codegen = new TypeScriptFetchClientCodegen();
+        codegen.processOpts();
         OpenAPI openAPI = TestUtils.createOpenAPIWithOneSchema("sample", model);
         codegen.setOpenAPI(openAPI);
         final CodegenModel cm = codegen.fromModel("sample", model);
diff --git a/samples/client/petstore/typescript-fetch/builds/without-runtime-checks/src/models/index.ts b/samples/client/petstore/typescript-fetch/builds/without-runtime-checks/src/models/index.ts
index 8d8f621b1ba5..8eef2399cc20 100644
--- a/samples/client/petstore/typescript-fetch/builds/without-runtime-checks/src/models/index.ts
+++ b/samples/client/petstore/typescript-fetch/builds/without-runtime-checks/src/models/index.ts
@@ -70,10 +70,10 @@ export interface Order {
     quantity?: number;
     /**
      * 
-     * @type {Date}
+     * @type {string}
      * @memberof Order
      */
-    shipDate?: Date;
+    shipDate?: string;
     /**
      * Order Status
      * @type {string}