diff --git a/packages/aws-cdk-lib/aws-elasticloadbalancingv2/lib/alb/application-load-balancer.ts b/packages/aws-cdk-lib/aws-elasticloadbalancingv2/lib/alb/application-load-balancer.ts
index 43af694e9ae20..bb6f2cfbefb8d 100644
--- a/packages/aws-cdk-lib/aws-elasticloadbalancingv2/lib/alb/application-load-balancer.ts
+++ b/packages/aws-cdk-lib/aws-elasticloadbalancingv2/lib/alb/application-load-balancer.ts
@@ -127,6 +127,11 @@ export class ApplicationLoadBalancer extends BaseLoadBalancer implements IApplic
     if (props.dropInvalidHeaderFields) {this.setAttribute('routing.http.drop_invalid_header_fields.enabled', 'true'); }
     if (props.desyncMitigationMode !== undefined) {this.setAttribute('routing.http.desync_mitigation_mode', props.desyncMitigationMode); }
     if (props.clientKeepAlive !== undefined) {
+      const clientKeepAliveInMillis = props.clientKeepAlive.toMilliseconds();
+      if (clientKeepAliveInMillis < 1000) {
+        throw new Error(`\'clientKeepAlive\' must be between 60 and 604800 seconds. Got: ${clientKeepAliveInMillis} milliseconds`);
+      }
+
       const clientKeepAliveInSeconds = props.clientKeepAlive.toSeconds();
       if (clientKeepAliveInSeconds < 60 || clientKeepAliveInSeconds > 604800) {
         throw new Error(`\'clientKeepAlive\' must be between 60 and 604800 seconds. Got: ${clientKeepAliveInSeconds} seconds`);
diff --git a/packages/aws-cdk-lib/aws-elasticloadbalancingv2/test/alb/load-balancer.test.ts b/packages/aws-cdk-lib/aws-elasticloadbalancingv2/test/alb/load-balancer.test.ts
index 119fa890527bc..54f2b5b1a4b7d 100644
--- a/packages/aws-cdk-lib/aws-elasticloadbalancingv2/test/alb/load-balancer.test.ts
+++ b/packages/aws-cdk-lib/aws-elasticloadbalancingv2/test/alb/load-balancer.test.ts
@@ -112,7 +112,7 @@ describe('tests', () => {
     });
   });
 
-  test.each([59, 604801])('throw error for invalid clientKeepAlive', (duration) => {
+  test.each([59, 604801])('throw error for invalid clientKeepAlive in seconds', (duration) => {
     // GIVEN
     const stack = new cdk.Stack();
     const vpc = new ec2.Vpc(stack, 'Stack');
@@ -126,6 +126,20 @@ describe('tests', () => {
     }).toThrow(`\'clientKeepAlive\' must be between 60 and 604800 seconds. Got: ${duration} seconds`);
   });
 
+  test('throw errer for invalid clientKeepAlive in milliseconds', () => {
+    // GIVEN
+    const stack = new cdk.Stack();
+    const vpc = new ec2.Vpc(stack, 'Stack');
+
+    // THEN
+    expect(() => {
+      new elbv2.ApplicationLoadBalancer(stack, 'LB', {
+        vpc,
+        clientKeepAlive: cdk.Duration.millis(100),
+      });
+    }).toThrow('\'clientKeepAlive\' must be between 60 and 604800 seconds. Got: 100 milliseconds');
+  });
+
   describe('Desync mitigation mode', () => {
     test('Defensive', () => {
       // GIVEN