diff --git a/packages/@aws-cdk/aws-rds/lib/cluster.ts b/packages/@aws-cdk/aws-rds/lib/cluster.ts
index 3ba13451e8731..f3f9300788e1c 100644
--- a/packages/@aws-cdk/aws-rds/lib/cluster.ts
+++ b/packages/@aws-cdk/aws-rds/lib/cluster.ts
@@ -227,6 +227,9 @@ interface DatabaseClusterBaseProps {
  * A new or imported clustered database.
  */
 export abstract class DatabaseClusterBase extends Resource implements IDatabaseCluster {
+  // only required because of JSII bug: https://github.com/aws/jsii/issues/2040
+  public abstract readonly engine?: IClusterEngine;
+
   /**
    * Identifier of the cluster
    */
diff --git a/packages/@aws-cdk/aws-rds/lib/instance.ts b/packages/@aws-cdk/aws-rds/lib/instance.ts
index bfc5ac47f1b24..1479fa2fafe40 100644
--- a/packages/@aws-cdk/aws-rds/lib/instance.ts
+++ b/packages/@aws-cdk/aws-rds/lib/instance.ts
@@ -135,6 +135,8 @@ export abstract class DatabaseInstanceBase extends Resource implements IDatabase
   public abstract readonly dbInstanceEndpointAddress: string;
   public abstract readonly dbInstanceEndpointPort: string;
   public abstract readonly instanceEndpoint: Endpoint;
+  // only required because of JSII bug: https://github.com/aws/jsii/issues/2040
+  public abstract readonly engine?: IInstanceEngine;
   protected abstract enableIamAuthentication?: boolean;
 
   /**
@@ -1096,6 +1098,7 @@ export class DatabaseInstanceReadReplica extends DatabaseInstanceNew implements
   public readonly dbInstanceEndpointAddress: string;
   public readonly dbInstanceEndpointPort: string;
   public readonly instanceEndpoint: Endpoint;
+  public readonly engine?: IInstanceEngine = undefined;
   protected readonly instanceType: ec2.InstanceType;
 
   constructor(scope: Construct, id: string, props: DatabaseInstanceReadReplicaProps) {