diff --git a/packages/@aws-cdk/aws-ec2/lib/security-group.ts b/packages/@aws-cdk/aws-ec2/lib/security-group.ts
index e3b63b42f48af..ab66118204d2c 100644
--- a/packages/@aws-cdk/aws-ec2/lib/security-group.ts
+++ b/packages/@aws-cdk/aws-ec2/lib/security-group.ts
@@ -432,7 +432,7 @@ export class SecurityGroup extends SecurityGroupBase {
         vpcId: options.vpc?.vpcId,
       },
       dummyValue: {
-        securityGroupId: 'sg-12345',
+        securityGroupId: 'sg-12345678',
         allowAllOutbound: true,
       } as cxapi.SecurityGroupContextResponse,
     }).value;
diff --git a/packages/@aws-cdk/aws-ec2/test/security-group.test.ts b/packages/@aws-cdk/aws-ec2/test/security-group.test.ts
index a480c53f58dfa..1263c904bb0df 100644
--- a/packages/@aws-cdk/aws-ec2/test/security-group.test.ts
+++ b/packages/@aws-cdk/aws-ec2/test/security-group.test.ts
@@ -528,7 +528,7 @@ describe('security group', () => {
 
     const securityGroup = SecurityGroup.fromLookup(stack, 'stack', 'sg-1234');
 
-    expect(securityGroup.securityGroupId).toEqual('sg-12345');
+    expect(securityGroup.securityGroupId).toEqual('sg-12345678');
     expect(securityGroup.allowAllOutbound).toEqual(true);
 
   });
@@ -547,7 +547,7 @@ describe('security group', () => {
     const securityGroup = SecurityGroup.fromLookupById(stack, 'SG1', 'sg-12345');
 
     // THEN
-    expect(securityGroup.securityGroupId).toEqual('sg-12345');
+    expect(securityGroup.securityGroupId).toEqual('sg-12345678');
     expect(securityGroup.allowAllOutbound).toEqual(true);
 
   });
@@ -571,7 +571,7 @@ describe('security group', () => {
     const securityGroup = SecurityGroup.fromLookupByName(stack, 'SG1', 'sg-12345', vpc);
 
     // THEN
-    expect(securityGroup.securityGroupId).toEqual('sg-12345');
+    expect(securityGroup.securityGroupId).toEqual('sg-12345678');
     expect(securityGroup.allowAllOutbound).toEqual(true);
 
   });
@@ -595,7 +595,7 @@ describe('security group', () => {
     const securityGroup = SecurityGroup.fromLookupByName(stack, 'SG1', 'my-security-group', vpc);
 
     // THEN
-    expect(securityGroup.securityGroupId).toEqual('sg-12345');
+    expect(securityGroup.securityGroupId).toEqual('sg-12345678');
     expect(securityGroup.allowAllOutbound).toEqual(true);
 
   });