diff --git a/packages/@aws-cdk/core/lib/asset-staging.ts b/packages/@aws-cdk/core/lib/asset-staging.ts
index ee1f2bafc6a04..502c0c10b0364 100644
--- a/packages/@aws-cdk/core/lib/asset-staging.ts
+++ b/packages/@aws-cdk/core/lib/asset-staging.ts
@@ -555,7 +555,7 @@ function calculateCacheKey<A extends object>(props: A): string {
  * Recursively sort object keys
  */
 function sortObject(object: { [key: string]: any }): { [key: string]: any } {
-  if (typeof object !== 'object' || object instanceof Array) {
+  if (typeof object !== 'object' || Array.isArray(object)) {
     return object;
   }
   const ret: { [key: string]: any } = {};
diff --git a/packages/@aws-cdk/core/lib/private/cloudformation-lang.ts b/packages/@aws-cdk/core/lib/private/cloudformation-lang.ts
index 82d2809255806..8c8321d7ebfa0 100644
--- a/packages/@aws-cdk/core/lib/private/cloudformation-lang.ts
+++ b/packages/@aws-cdk/core/lib/private/cloudformation-lang.ts
@@ -167,6 +167,7 @@ function tokenAwareStringify(root: any, space: number, ctx: IResolveContext) {
     if (Array.isArray(obj)) {
       return renderCollection('[', ']', obj, recurse);
     }
+    // eslint-disable-next-line no-instanceof/no-instanceof
     if (typeof obj === 'object' && obj != null && !(obj instanceof Date)) {
       // Treat as an intrinsic if this LOOKS like a CFN intrinsic (`{ Ref: ... }`)
       // AND it's the result of a token resolution. Otherwise, we just treat this
diff --git a/packages/@aws-cdk/core/lib/private/resolve.ts b/packages/@aws-cdk/core/lib/private/resolve.ts
index e809763b72e64..15ac3a9e09347 100644
--- a/packages/@aws-cdk/core/lib/private/resolve.ts
+++ b/packages/@aws-cdk/core/lib/private/resolve.ts
@@ -184,6 +184,7 @@ export function resolve(obj: any, options: IResolveOptions): any {
   // primitives - as-is
   //
 
+  // eslint-disable-next-line no-instanceof/no-instanceof
   if (typeof(obj) !== 'object' || obj instanceof Date) {
     return obj;
   }
diff --git a/packages/@aws-cdk/core/lib/private/synthesis.ts b/packages/@aws-cdk/core/lib/private/synthesis.ts
index 52738c1cf9cca..2515b26544271 100644
--- a/packages/@aws-cdk/core/lib/private/synthesis.ts
+++ b/packages/@aws-cdk/core/lib/private/synthesis.ts
@@ -182,7 +182,7 @@ function synthesizeTree(root: IConstruct, builder: cxapi.CloudAssemblyBuilder, v
 
     if (Stack.isStack(construct)) {
       construct.synthesizer.synthesize(session);
-    } else if (construct instanceof TreeMetadata) {
+    } else if (TreeMetadata.isTreeMetadata(construct)) {
       construct._synthesizeTree(session);
     } else {
       const custom = getCustomSynthesis(construct);
diff --git a/packages/@aws-cdk/core/lib/private/tree-metadata.ts b/packages/@aws-cdk/core/lib/private/tree-metadata.ts
index 8421fd3933aea..b5dbfa2fce171 100644
--- a/packages/@aws-cdk/core/lib/private/tree-metadata.ts
+++ b/packages/@aws-cdk/core/lib/private/tree-metadata.ts
@@ -10,6 +10,8 @@ import { ConstructInfo, constructInfoFromConstruct } from './runtime-info';
 
 const FILE_PATH = 'tree.json';
 
+const TREE_METADATA_SYMBOL = Symbol.for('@aws-cdk/core.TreeMetadata');
+
 /**
  * Construct that is automatically attached to the top-level `App`.
  * This generates, as part of synthesis, a file containing the construct tree and the metadata for each node in the tree.
@@ -17,6 +19,13 @@ const FILE_PATH = 'tree.json';
  *
  */
 export class TreeMetadata extends Construct {
+  /**
+   * Return whether the given object is a TreeMetadata.
+   */
+  public static isTreeMetadata(x: any): x is TreeMetadata {
+    return x !== null && typeof(x) === 'object' && TREE_METADATA_SYMBOL in x;
+  }
+
   constructor(scope: Construct) {
     super(scope, 'Tree');
   }
@@ -98,3 +107,12 @@ interface Node {
    */
   readonly constructInfo?: ConstructInfo;
 }
+
+/**
+ * Mark all instances of 'TreeMetadata'.
+ */
+Object.defineProperty(TreeMetadata.prototype, TREE_METADATA_SYMBOL, {
+  value: true,
+  enumerable: false,
+  writable: false,
+});
diff --git a/packages/@aws-cdk/core/lib/runtime.ts b/packages/@aws-cdk/core/lib/runtime.ts
index 84edb8f6e5728..e8cfd91a14085 100644
--- a/packages/@aws-cdk/core/lib/runtime.ts
+++ b/packages/@aws-cdk/core/lib/runtime.ts
@@ -231,6 +231,7 @@ export function validateBoolean(x: any): ValidationResult {
 }
 
 export function validateDate(x: any): ValidationResult {
+  // eslint-disable-next-line no-instanceof/no-instanceof
   if (canInspect(x) && !(x instanceof Date)) {
     return new ValidationResult(`${JSON.stringify(x)} should be a Date`);
   }
diff --git a/packages/@aws-cdk/core/test/stack-synthesis/clicreds-synthesis.test.ts b/packages/@aws-cdk/core/test/stack-synthesis/clicreds-synthesis.test.ts
index 3fab5ef7e0b5f..19a00351fef76 100644
--- a/packages/@aws-cdk/core/test/stack-synthesis/clicreds-synthesis.test.ts
+++ b/packages/@aws-cdk/core/test/stack-synthesis/clicreds-synthesis.test.ts
@@ -239,7 +239,7 @@ function evalCFN(value: any) {
 }
 
 function isAssetManifest(x: cxapi.CloudArtifact): x is cxapi.AssetManifestArtifact {
-  return x instanceof cxapi.AssetManifestArtifact;
+  return cxapi.AssetManifestArtifact.isAssetManifestArtifact(x);
 }
 
 function getAssetManifest(asm: cxapi.CloudAssembly): cxapi.AssetManifestArtifact {
diff --git a/packages/@aws-cdk/core/test/stack-synthesis/new-style-synthesis.test.ts b/packages/@aws-cdk/core/test/stack-synthesis/new-style-synthesis.test.ts
index 4ced5a1e9afeb..ddf747aa0b03c 100644
--- a/packages/@aws-cdk/core/test/stack-synthesis/new-style-synthesis.test.ts
+++ b/packages/@aws-cdk/core/test/stack-synthesis/new-style-synthesis.test.ts
@@ -393,7 +393,7 @@ function evalCFN(value: any) {
 }
 
 function isAssetManifest(x: cxapi.CloudArtifact): x is cxapi.AssetManifestArtifact {
-  return x instanceof cxapi.AssetManifestArtifact;
+  return cxapi.AssetManifestArtifact.isAssetManifestArtifact(x);
 }
 
 function getAssetManifest(asm: cxapi.CloudAssembly): cxapi.AssetManifestArtifact {
diff --git a/packages/@aws-cdk/core/test/stage.test.ts b/packages/@aws-cdk/core/test/stage.test.ts
index 6c7f27c8cfec4..14f47d42e275b 100644
--- a/packages/@aws-cdk/core/test/stage.test.ts
+++ b/packages/@aws-cdk/core/test/stage.test.ts
@@ -50,7 +50,7 @@ describe('stage', () => {
     // THEN -- app manifest contains a nested cloud assembly
     const appAsm = app.synth();
 
-    const artifact = appAsm.artifacts.find(x => x instanceof cxapi.NestedCloudAssemblyArtifact);
+    const artifact = appAsm.artifacts.find(x => cxapi.NestedCloudAssemblyArtifact.isNestedCloudAssemblyArtifact(x));
     expect(artifact).toBeDefined();
 
 
diff --git a/packages/@aws-cdk/cx-api/lib/artifacts/cloudformation-artifact.ts b/packages/@aws-cdk/cx-api/lib/artifacts/cloudformation-artifact.ts
index f601131d9f532..a9bd5dc46edf8 100644
--- a/packages/@aws-cdk/cx-api/lib/artifacts/cloudformation-artifact.ts
+++ b/packages/@aws-cdk/cx-api/lib/artifacts/cloudformation-artifact.ts
@@ -5,7 +5,16 @@ import { CloudArtifact } from '../cloud-artifact';
 import type { CloudAssembly } from '../cloud-assembly';
 import { Environment, EnvironmentUtils } from '../environment';
 
+const CLOUDFORMATION_STACK_ARTIFACT_SYMBOL = Symbol.for('@aws-cdk/cx-api.CloudFormationStackArtifact');
+
 export class CloudFormationStackArtifact extends CloudArtifact {
+  /**
+   * Return whether the given object is a CloudFormationStackArtifact.
+   */
+  public static isCloudFormationStackArtifact(x: any): x is CloudFormationStackArtifact {
+    return x !== null && typeof(x) === 'object' && CLOUDFORMATION_STACK_ARTIFACT_SYMBOL in x;
+  }
+
   /**
    * The file name of the template.
    */
@@ -183,3 +192,12 @@ export class CloudFormationStackArtifact extends CloudArtifact {
     return ret;
   }
 }
+
+/**
+ * Mark all instances of 'CloudFormationStackArtifact'.
+ */
+Object.defineProperty(CloudFormationStackArtifact.prototype, CLOUDFORMATION_STACK_ARTIFACT_SYMBOL, {
+  value: true,
+  enumerable: false,
+  writable: false,
+});
\ No newline at end of file
diff --git a/packages/@aws-cdk/cx-api/lib/artifacts/nested-cloud-assembly-artifact.ts b/packages/@aws-cdk/cx-api/lib/artifacts/nested-cloud-assembly-artifact.ts
index 61684316949d4..f604b1a4ba19f 100644
--- a/packages/@aws-cdk/cx-api/lib/artifacts/nested-cloud-assembly-artifact.ts
+++ b/packages/@aws-cdk/cx-api/lib/artifacts/nested-cloud-assembly-artifact.ts
@@ -3,10 +3,19 @@ import * as cxschema from '@aws-cdk/cloud-assembly-schema';
 import { CloudArtifact } from '../cloud-artifact';
 import type { CloudAssembly } from '../cloud-assembly';
 
+const NESTED_CLOUD_ASSEMBLY_ARTIFACT_SYMBOL = Symbol.for('@aws-cdk/cx-api.NestedCloudAssemblyArtifact');
+
 /**
  * Asset manifest is a description of a set of assets which need to be built and published
  */
 export class NestedCloudAssemblyArtifact extends CloudArtifact {
+  /**
+   * Return whether the given object is a NestedCloudAssemblyArtifact.
+   */
+  public static isNestedCloudAssemblyArtifact(x: any): x is NestedCloudAssemblyArtifact {
+    return x !== null && typeof(x) === 'object' && NESTED_CLOUD_ASSEMBLY_ARTIFACT_SYMBOL in x;
+  }
+
   /**
    * The relative directory name of the asset manifest
    */
@@ -40,4 +49,13 @@ export interface NestedCloudAssemblyArtifact {
   readonly nestedAssembly: CloudAssembly;
 
   // Declared in a different file
-}
\ No newline at end of file
+}
+
+/**
+ * Mark all instances of 'NestedCloudAssemblyArtifact'.
+ */
+Object.defineProperty(NestedCloudAssemblyArtifact.prototype, NESTED_CLOUD_ASSEMBLY_ARTIFACT_SYMBOL, {
+  value: true,
+  enumerable: false,
+  writable: false,
+});
\ No newline at end of file
diff --git a/packages/@aws-cdk/cx-api/lib/artifacts/tree-cloud-artifact.ts b/packages/@aws-cdk/cx-api/lib/artifacts/tree-cloud-artifact.ts
index 689f3468ca252..85f3edeb7564a 100644
--- a/packages/@aws-cdk/cx-api/lib/artifacts/tree-cloud-artifact.ts
+++ b/packages/@aws-cdk/cx-api/lib/artifacts/tree-cloud-artifact.ts
@@ -2,7 +2,16 @@ import * as cxschema from '@aws-cdk/cloud-assembly-schema';
 import { CloudArtifact } from '../cloud-artifact';
 import { CloudAssembly } from '../cloud-assembly';
 
+const TREE_CLOUD_ARTIFACT_SYMBOL = Symbol.for('@aws-cdk/cx-api.TreeCloudArtifact');
+
 export class TreeCloudArtifact extends CloudArtifact {
+  /**
+   * Return whether the given object is a TreeCloudArtifact.
+   */
+  public static isTreeCloudArtifact(x: any): x is TreeCloudArtifact {
+    return x !== null && typeof(x) === 'object' && TREE_CLOUD_ARTIFACT_SYMBOL in x;
+  }
+
   public readonly file: string;
 
   constructor(assembly: CloudAssembly, name: string, artifact: cxschema.ArtifactManifest) {
@@ -14,4 +23,13 @@ export class TreeCloudArtifact extends CloudArtifact {
     }
     this.file = properties.file;
   }
-}
\ No newline at end of file
+}
+
+/**
+ * Mark all instances of 'TreeCloudArtifact'.
+ */
+Object.defineProperty(TreeCloudArtifact.prototype, TREE_CLOUD_ARTIFACT_SYMBOL, {
+  value: true,
+  enumerable: false,
+  writable: false,
+});
diff --git a/packages/@aws-cdk/cx-api/lib/cloud-assembly.ts b/packages/@aws-cdk/cx-api/lib/cloud-assembly.ts
index 70f4ecc850f36..61f6e19905e92 100644
--- a/packages/@aws-cdk/cx-api/lib/cloud-assembly.ts
+++ b/packages/@aws-cdk/cx-api/lib/cloud-assembly.ts
@@ -80,7 +80,7 @@ export class CloudAssembly {
    * @returns a `CloudFormationStackArtifact` object.
    */
   public getStackByName(stackName: string): CloudFormationStackArtifact {
-    const artifacts = this.artifacts.filter(a => a instanceof CloudFormationStackArtifact && a.stackName === stackName);
+    const artifacts = this.artifacts.filter(a => CloudFormationStackArtifact.isCloudFormationStackArtifact(a) && a.stackName === stackName);
     if (!artifacts || artifacts.length === 0) {
       throw new Error(`Unable to find stack with stack name "${stackName}"`);
     }
@@ -115,7 +115,7 @@ export class CloudAssembly {
       throw new Error(`Unable to find artifact with id "${artifactId}"`);
     }
 
-    if (!(artifact instanceof CloudFormationStackArtifact)) {
+    if (!CloudFormationStackArtifact.isCloudFormationStackArtifact(artifact)) {
       throw new Error(`Artifact ${artifactId} is not a CloudFormation stack`);
     }
 
@@ -154,7 +154,7 @@ export class CloudAssembly {
       throw new Error(`Unable to find artifact with id "${artifactId}"`);
     }
 
-    if (!(artifact instanceof NestedCloudAssemblyArtifact)) {
+    if (!NestedCloudAssemblyArtifact.isNestedCloudAssemblyArtifact(artifact)) {
       throw new Error(`Found artifact '${artifactId}' but it's not a nested cloud assembly`);
     }
 
@@ -184,7 +184,7 @@ export class CloudAssembly {
     }
     const tree = trees[0];
 
-    if (!(tree instanceof TreeCloudArtifact)) {
+    if (!TreeCloudArtifact.isTreeCloudArtifact(tree)) {
       throw new Error('"Tree" artifact is not of expected type');
     }
 
@@ -195,22 +195,14 @@ export class CloudAssembly {
    * @returns all the CloudFormation stack artifacts that are included in this assembly.
    */
   public get stacks(): CloudFormationStackArtifact[] {
-    return this.artifacts.filter(isCloudFormationStackArtifact);
-
-    function isCloudFormationStackArtifact(x: any): x is CloudFormationStackArtifact {
-      return x instanceof CloudFormationStackArtifact;
-    }
+    return this.artifacts.filter(CloudFormationStackArtifact.isCloudFormationStackArtifact);
   }
 
   /**
    * The nested assembly artifacts in this assembly
    */
   public get nestedAssemblies(): NestedCloudAssemblyArtifact[] {
-    return this.artifacts.filter(isNestedCloudAssemblyArtifact);
-
-    function isNestedCloudAssemblyArtifact(x: any): x is NestedCloudAssemblyArtifact {
-      return x instanceof NestedCloudAssemblyArtifact;
-    }
+    return this.artifacts.filter(NestedCloudAssemblyArtifact.isNestedCloudAssemblyArtifact);
   }
 
   private validateDeps() {
diff --git a/tools/@aws-cdk/cfn2ts/lib/genspec.ts b/tools/@aws-cdk/cfn2ts/lib/genspec.ts
index 7f63778097d59..d14cf225f241b 100644
--- a/tools/@aws-cdk/cfn2ts/lib/genspec.ts
+++ b/tools/@aws-cdk/cfn2ts/lib/genspec.ts
@@ -111,7 +111,7 @@ export class Attribute {
  * Example: AWS::EC2 -> ec2
  */
 export function packageName(module: SpecName | string): string {
-  if (module instanceof SpecName) {
+  if (SpecName.isSpecName(module)) {
     module = module.module;
   }
 
diff --git a/tools/@aws-cdk/cfn2ts/lib/spec-utils.ts b/tools/@aws-cdk/cfn2ts/lib/spec-utils.ts
index 7637bc199439a..366c293f15893 100644
--- a/tools/@aws-cdk/cfn2ts/lib/spec-utils.ts
+++ b/tools/@aws-cdk/cfn2ts/lib/spec-utils.ts
@@ -1,12 +1,21 @@
 import { schema } from '@aws-cdk/cfnspec';
 import { joinIf } from './util';
 
+const SPEC_NAME_SYMBOL = Symbol.for('@aws-cdk/cfn2ts.SpecName');
+
 /**
  * Name of an object in the CloudFormation spec
  *
  * This refers to a Resource, parsed from a string like 'AWS::S3::Bucket'.
  */
 export class SpecName {
+  /**
+   * Return whether the given object is a SpecName.
+   */
+  public static isSpecName(x: any): x is SpecName {
+    return x !== null && typeof(x) === 'object' && SPEC_NAME_SYMBOL in x;
+  }
+
   /**
    * Parse a string representing a name from the CloudFormation spec to a CfnName object
    */
@@ -36,6 +45,7 @@ export class SpecName {
   }
 }
 
+
 /**
  * Name of a property type or attribute in the CloudFormation spec.
  *
@@ -121,3 +131,12 @@ function primitiveScalarTypeNames(spec: schema.ScalarProperty): string[] {
   }
   return [];
 }
+
+/**
+ * Mark all instances of 'SpecName'.
+ */
+Object.defineProperty(SpecName.prototype, SPEC_NAME_SYMBOL, {
+  value: true,
+  enumerable: false,
+  writable: false,
+});