diff --git a/packages/@aws-cdk/aws-appsync/README.md b/packages/@aws-cdk/aws-appsync/README.md
index 60e360f2312f5..1b2717610eb4f 100644
--- a/packages/@aws-cdk/aws-appsync/README.md
+++ b/packages/@aws-cdk/aws-appsync/README.md
@@ -330,7 +330,7 @@ const zone = route53.HostedZone.fromHostedZoneAttributes(this, `HostedZone`, {
 new route53.CnameRecord(this, `CnameApiRecord`, {
   recordName: 'api',
   zone,
-  domainName: api.appSyncDomainName!,
+  domainName: api.appSyncDomainName,
 });
 ```
 
diff --git a/packages/@aws-cdk/aws-appsync/lib/graphqlapi.ts b/packages/@aws-cdk/aws-appsync/lib/graphqlapi.ts
index 2155e3a37b417..5736f888fbf73 100644
--- a/packages/@aws-cdk/aws-appsync/lib/graphqlapi.ts
+++ b/packages/@aws-cdk/aws-appsync/lib/graphqlapi.ts
@@ -470,13 +470,6 @@ export class GraphqlApi extends GraphqlApiBase {
    */
   public readonly apiKey?: string;
 
-  /**
-   * the associated custom AppSync domain, if present
-   *
-   * @default - no custom associated domain
-   */
-  public readonly appSyncDomainName?: string;
-
   /**
    * the CloudWatch Log Group for this API
    */
@@ -485,6 +478,7 @@ export class GraphqlApi extends GraphqlApiBase {
   private schemaResource: CfnGraphQLSchema;
   private api: CfnGraphQLApi;
   private apiKeyResource?: CfnApiKey;
+  private domainNameResource?: CfnDomainName;
 
   constructor(scope: Construct, id: string, props: GraphqlApiProps) {
     super(scope, id);
@@ -517,18 +511,17 @@ export class GraphqlApi extends GraphqlApiBase {
     this.schemaResource = this.schema.bind(this);
 
     if (props.domainName) {
-      const domainName = new CfnDomainName(this, 'DomainName', {
+      this.domainNameResource = new CfnDomainName(this, 'DomainName', {
         domainName: props.domainName.domainName,
         certificateArn: props.domainName.certificate.certificateArn,
         description: `domain for ${this.name} at ${this.graphqlUrl}`,
       });
-      this.appSyncDomainName = domainName.attrAppSyncDomainName;
       const domainNameAssociation = new CfnDomainNameApiAssociation(this, 'DomainAssociation', {
         domainName: props.domainName.domainName,
         apiId: this.apiId,
       });
 
-      domainNameAssociation.addDependsOn(domainName);
+      domainNameAssociation.addDependsOn(this.domainNameResource);
     }
 
     if (modes.some((mode) => mode.authorizationType === AuthorizationType.API_KEY)) {
@@ -781,4 +774,15 @@ export class GraphqlApi extends GraphqlApiBase {
   public addSubscription(fieldName: string, field: ResolvableField): ObjectType {
     return this.schema.addSubscription(fieldName, field);
   }
+
+
+  /**
+   * The AppSyncDomainName of the associated custom domain
+   */
+  public get appSyncDomainName(): string {
+    if (!this.domainNameResource) {
+      throw new Error('Cannot retrieve the appSyncDomainName without a domainName configuration');
+    }
+    return this.domainNameResource.attrAppSyncDomainName;
+  }
 }
diff --git a/packages/@aws-cdk/aws-appsync/test/appsync-domain.test.ts b/packages/@aws-cdk/aws-appsync/test/appsync-domain.test.ts
index 279a24e8be1d3..ddc3041670fa0 100644
--- a/packages/@aws-cdk/aws-appsync/test/appsync-domain.test.ts
+++ b/packages/@aws-cdk/aws-appsync/test/appsync-domain.test.ts
@@ -41,7 +41,7 @@ describe('Tests of AppSync Domain Name', () => {
     );
   });
 
-  test('domainNameAppSyncDomainName exposes the domain of the associated AWS::AppSync::DomainName', () => {
+  test('appSyncDomainName exposes the domain of the associated AWS::AppSync::DomainName', () => {
     const api = new appsync.GraphqlApi(stack, 'baseApi', {
       name: 'api',
       schema: appsync.Schema.fromAsset(
@@ -55,4 +55,15 @@ describe('Tests of AppSync Domain Name', () => {
 
     expect(stack.resolve(api.appSyncDomainName)).toEqual({ 'Fn::GetAtt': ['baseApiDomainName52E3D63D', 'AppSyncDomainName'] });
   });
+
+  test('appSyncDomainName should throw an error when no custom domain has been configured', () => {
+    const api = new appsync.GraphqlApi(stack, 'baseApi', {
+      name: 'api',
+      schema: appsync.Schema.fromAsset(
+        path.join(__dirname, 'appsync.test.graphql'),
+      ),
+    });
+
+    expect(() => api.appSyncDomainName).toThrow('Cannot retrieve the appSyncDomainName without a domainName configuration');
+  });
 });