diff --git a/__tests__/index.ts b/__tests__/index.ts
index 76ec43d..ed9771a 100644
--- a/__tests__/index.ts
+++ b/__tests__/index.ts
@@ -14,7 +14,7 @@ hash.update('foo bar');
 
 const SIMPLE_TYPES: PlainObject = {
   boolean: true,
-  error: new Error('boom'),
+  error: new TypeError('boom'),
   fn() {
     return 'foo';
   },
@@ -53,7 +53,7 @@ const COMPLEX_TYPES: PlainObject = {
   })('foo', 'bar', 'baz'),
   array: ['foo', { bar: 'baz' }],
   arrayBuffer: new ArrayBuffer(8),
-  buffer: new Buffer('this is a test buffer'),
+  buffer: Buffer.from('this is a test buffer'),
   customPrototype: Object.create({
     method() {
       return 'foo';
@@ -62,22 +62,22 @@ const COMPLEX_TYPES: PlainObject = {
   }),
   dataView: new DataView(new ArrayBuffer(16)),
   date: new Date(),
-  float32Array: new Float32Array([12, 15]),
-  float64Array: new Float64Array([12, 15]),
+  float32Array: new Float32Array([1, 2]),
+  float64Array: new Float64Array([3, 4]),
   hash,
-  int8Array: new Int8Array([12, 15]),
-  int16Array: new Int16Array([12, 15]),
-  int32Array: new Int32Array([12, 15]),
+  int8Array: new Int8Array([5, 6]),
+  int16Array: new Int16Array([7, 8]),
+  int32Array: new Int32Array([9, 10]),
   map: new Map().set('foo', { bar: { baz: 'quz' } }),
   object: { foo: { bar: 'baz' } },
   regexp: /foo/,
   set: new Set().add('foo').add({ bar: { baz: 'quz' } }),
   // Disabling, as jest fails intermittently with blob construction.
   // blob: new Blob(['<a id="a">hey!</a>'], {type : 'text/html'}),
-  uint8Array: new Uint8Array([12, 15]),
-  uint8ClampedArray: new Uint8ClampedArray([12, 15]),
-  uint16Array: new Uint16Array([12, 15]),
-  uint32Array: new Uint32Array([12, 15]),
+  uint8Array: new Uint8Array([11, 12]),
+  uint8ClampedArray: new Uint8ClampedArray([13, 14]),
+  uint16Array: new Uint16Array([15, 16]),
+  uint32Array: new Uint32Array([17, 18]),
 };
 
 Object.defineProperties(COMPLEX_TYPES, {
@@ -168,8 +168,8 @@ describe('copy', () => {
     const properties = [].concat(
       Object.keys(SIMPLE_TYPES),
       Object.getOwnPropertySymbols(SIMPLE_TYPES).filter((symbol) =>
-        Object.prototype.propertyIsEnumerable.call(SIMPLE_TYPES, symbol),
-      ),
+        Object.prototype.propertyIsEnumerable.call(SIMPLE_TYPES, symbol)
+      )
     );
 
     properties.forEach((property: string | symbol) => {
@@ -192,7 +192,7 @@ describe('copy', () => {
     const properties = [
       ...Object.keys(COMPLEX_TYPES),
       ...Object.getOwnPropertySymbols(COMPLEX_TYPES).filter((symbol) =>
-        Object.prototype.propertyIsEnumerable.call(COMPLEX_TYPES, symbol),
+        Object.prototype.propertyIsEnumerable.call(COMPLEX_TYPES, symbol)
       ),
     ];
 
@@ -202,7 +202,7 @@ describe('copy', () => {
         expect({ ...result[property] }).toEqual({ ...COMPLEX_TYPES[property] });
       } else if (property === 'customPrototype') {
         expect(Object.getPrototypeOf(result[property])).toBe(
-          Object.getPrototypeOf(COMPLEX_TYPES[property]),
+          Object.getPrototypeOf(COMPLEX_TYPES[property])
         );
         expect(result[property]).toEqual(COMPLEX_TYPES[property]);
       } else {
@@ -226,42 +226,6 @@ describe('copy', () => {
     expect(result).toEqual(SPECIAL_TYPES);
   });
 
-  it('will handle when buffers are not supported', () => {
-    const cleanComplexTypes = Object.keys(COMPLEX_TYPES).reduce(
-      (types: PlainObject, key) => {
-        if (
-          key !== 'arguments' &&
-          key !== 'arrayBuffer' &&
-          key !== 'buffer' &&
-          key !== 'dataView' &&
-          !/float(.*)Array/.test(key) &&
-          !/int(.*)Array/.test(key)
-        ) {
-          types[key] = COMPLEX_TYPES[key];
-        }
-
-        return types;
-      },
-      {},
-    );
-
-    const realm = {
-      Date: global.Date,
-      Error: global.Error,
-      Map: global.Map,
-      RegExp: global.RegExp,
-      Set: global.Set,
-      Blob: global.Blob,
-      WeakMap: global.WeakMap,
-      WeakSet: global.WeakSet,
-    } as typeof globalThis;
-
-    const result = copy(cleanComplexTypes, { realm });
-
-    expect(result).not.toBe(cleanComplexTypes);
-    expect(result).toEqual(cleanComplexTypes);
-  });
-
   it('will copy referenced objects', () => {
     const reusedObject = {
       name: 'I like trains!',
@@ -347,7 +311,7 @@ describe('copyStrict', () => {
 
     const properties = [].concat(
       Object.getOwnPropertyNames(SIMPLE_TYPES),
-      Object.getOwnPropertySymbols(SIMPLE_TYPES),
+      Object.getOwnPropertySymbols(SIMPLE_TYPES)
     );
 
     properties.forEach((property: string | symbol) => {
@@ -374,7 +338,7 @@ describe('copyStrict', () => {
 
     const properties = [].concat(
       Object.getOwnPropertyNames(complexTypes),
-      Object.getOwnPropertySymbols(complexTypes),
+      Object.getOwnPropertySymbols(complexTypes)
     );
 
     properties.forEach((property: string | symbol) => {
@@ -388,10 +352,10 @@ describe('copyStrict', () => {
         });
       } else if (property === 'customPrototype') {
         expect(Object.getPrototypeOf(result[property])).toBe(
-          Object.getPrototypeOf(COMPLEX_TYPES[property]),
+          Object.getPrototypeOf(COMPLEX_TYPES[property])
         );
         expect(Object.getPrototypeOf(result2[property])).toBe(
-          Object.getPrototypeOf(COMPLEX_TYPES[property]),
+          Object.getPrototypeOf(COMPLEX_TYPES[property])
         );
 
         expect(result[property]).toEqual(COMPLEX_TYPES[property]);
@@ -427,45 +391,6 @@ describe('copyStrict', () => {
     expect(result2).toEqual(SPECIAL_TYPES);
   });
 
-  it('will handle when buffers are not supported', () => {
-    const cleanComplexTypes = Object.keys(COMPLEX_TYPES).reduce(
-      (types: PlainObject, key) => {
-        if (
-          key !== 'arguments' &&
-          key !== 'arrayBuffer' &&
-          key !== 'buffer' &&
-          key !== 'dataView' &&
-          !/float(.*)Array/.test(key) &&
-          !/int(.*)Array/.test(key)
-        ) {
-          types[key] = COMPLEX_TYPES[key];
-        }
-
-        return types;
-      },
-      {},
-    );
-
-    const realm = {
-      Date: global.Date,
-      Error: global.Error,
-      Map: global.Map,
-      RegExp: global.RegExp,
-      Set: global.Set,
-      WeakMap: global.WeakMap,
-      WeakSet: global.WeakSet,
-    } as typeof globalThis;
-
-    const result = copy(cleanComplexTypes, { isStrict: true, realm });
-    const result2 = copyStrict(cleanComplexTypes, { realm });
-
-    expect(result).not.toBe(cleanComplexTypes);
-    expect(result2).not.toBe(cleanComplexTypes);
-
-    expect(result).toEqual(cleanComplexTypes);
-    expect(result2).toEqual(cleanComplexTypes);
-  });
-
   it('will copy referenced objects', () => {
     const reusedObject = {
       name: 'I like trains!',
diff --git a/__tests__/utils.ts b/__tests__/utils.ts
index cb072c7..2b7be8c 100644
--- a/__tests__/utils.ts
+++ b/__tests__/utils.ts
@@ -56,9 +56,8 @@ describe('createCache', () => {
 describe('getCleanClone', () => {
   it('will return a pure object when there is no constructor', () => {
     const object = Object.create(null);
-    const realm = global;
 
-    const result = utils.getCleanClone(object, realm);
+    const result = utils.getCleanClone(object);
 
     expect(result).not.toBe(object);
     expect(result).toEqual(object);
@@ -71,9 +70,7 @@ describe('getCleanClone', () => {
 
     object.__proto__ = null;
 
-    const realm = global;
-
-    const result = utils.getCleanClone(object, realm);
+    const result = utils.getCleanClone(object);
 
     expect(result).not.toBe(object);
     expect(result).toEqual(object);
@@ -83,9 +80,8 @@ describe('getCleanClone', () => {
 
   it('will return an empty POJO when the object passed is a POJO', () => {
     const object = { foo: 'bar' };
-    const realm = global;
 
-    const result = utils.getCleanClone(object, realm);
+    const result = utils.getCleanClone(object);
 
     expect(result).not.toBe(object);
     expect(result).toEqual({});
@@ -100,9 +96,7 @@ describe('getCleanClone', () => {
 
     object.foo = 'bar';
 
-    const realm = global;
-
-    const result = utils.getCleanClone(object, realm);
+    const result = utils.getCleanClone(object);
 
     expect(result).not.toBe(object);
     expect(result).toEqual({});
@@ -112,9 +106,8 @@ describe('getCleanClone', () => {
 
   it('will return an empty object with the given constructor when it is a global constructor', () => {
     const object = new Map();
-    const realm = global;
 
-    const result = utils.getCleanClone(object, realm);
+    const result = utils.getCleanClone(object);
 
     expect(result).not.toBe(object);
     expect(result).toEqual(new Map());
@@ -134,9 +127,8 @@ describe('getCleanClone', () => {
     }
 
     const object = new Foo('bar');
-    const realm = global;
 
-    const result = utils.getCleanClone(object, realm);
+    const result = utils.getCleanClone(object);
 
     expect(result).not.toBe(object);
     expect(result).toEqual(Object.create(Foo.prototype));
@@ -160,11 +152,10 @@ describe('getObjectCloneLoose', () => {
       foo: 'bar',
       [symbol]: 'blah',
     };
-    const realm = global;
     const handleCopy = jest.fn().mockImplementation((arg) => arg);
     const cache = utils.createCache();
 
-    const result = utils.getObjectCloneLoose(object, realm, handleCopy, cache);
+    const result = utils.getObjectCloneLoose(object, handleCopy, cache);
 
     Object.getOwnPropertySymbols = original;
 
@@ -174,7 +165,7 @@ describe('getObjectCloneLoose', () => {
         clone[key] = object[key as keyof typeof object];
 
         return clone;
-      }, {}),
+      }, {})
     );
 
     expect(handleCopy).toHaveBeenCalledTimes(Object.keys(object).length);
@@ -185,17 +176,16 @@ describe('getObjectCloneLoose', () => {
       bar: { baz: 'quz' },
       [Symbol('quz')]: 'blah',
     };
-    const realm = global;
     const handleCopy = jest.fn().mockImplementation((arg) => arg);
     const cache = utils.createCache();
 
-    const result = utils.getObjectCloneLoose(object, realm, handleCopy, cache);
+    const result = utils.getObjectCloneLoose(object, handleCopy, cache);
 
     expect(result).not.toBe(object);
     expect(result).toEqual(object);
 
     expect(handleCopy).toHaveBeenCalledTimes(
-      Object.keys(object).length + Object.getOwnPropertySymbols(object).length,
+      Object.keys(object).length + Object.getOwnPropertySymbols(object).length
     );
   });
 });
@@ -222,11 +212,10 @@ describe('getObjectCloneStrict', () => {
       value: 'blah',
     });
 
-    const realm = global;
     const handleCopy = jest.fn().mockImplementation((arg) => arg);
     const cache = utils.createCache();
 
-    const result = utils.getObjectCloneStrict(object, realm, handleCopy, cache);
+    const result = utils.getObjectCloneStrict(object, handleCopy, cache);
 
     Object.getOwnPropertySymbols = original;
 
@@ -238,12 +227,12 @@ describe('getObjectCloneStrict', () => {
 
           return clone;
         },
-        {},
-      ),
+        {}
+      )
     );
 
     expect(handleCopy).toHaveBeenCalledTimes(
-      Object.getOwnPropertyNames(object).length,
+      Object.getOwnPropertyNames(object).length
     );
   });
 
@@ -261,18 +250,17 @@ describe('getObjectCloneStrict', () => {
       value: 'blah',
     });
 
-    const realm = global;
     const handleCopy = jest.fn().mockImplementation((arg) => arg);
     const cache = utils.createCache();
 
-    const result = utils.getObjectCloneStrict(object, realm, handleCopy, cache);
+    const result = utils.getObjectCloneStrict(object, handleCopy, cache);
 
     expect(result).not.toBe(object);
     expect(result).toEqual(object);
 
     expect(handleCopy).toHaveBeenCalledTimes(
       Object.getOwnPropertyNames(object).length +
-        Object.getOwnPropertySymbols(object).length,
+        Object.getOwnPropertySymbols(object).length
     );
   });
 });
diff --git a/src/index.ts b/src/index.ts
index 5f8dff1..503b416 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -9,37 +9,13 @@ import type { Cache, InternalCopier, Realm } from './utils';
 
 export interface Options {
   isStrict?: boolean;
-  realm?: Realm;
 }
 
 export interface StrictOptions extends Omit<Options, 'isStrict'> {}
 
 const { isArray } = Array;
 const { assign, getPrototypeOf } = Object;
-
-const GLOBAL_THIS: Realm = (function () {
-  if (typeof globalThis !== 'undefined') {
-    return globalThis;
-  }
-
-  if (typeof self !== 'undefined') {
-    return self;
-  }
-
-  if (typeof window !== 'undefined') {
-    return window;
-  }
-
-  if (typeof global !== 'undefined') {
-    return global;
-  }
-
-  if (console && console.error) {
-    console.error('Unable to locate global object, returning "this".');
-  }
-
-  return this;
-})();
+const { toString } = Object.prototype;
 
 /**
  * Copy an value deeply as much as possible.
@@ -54,7 +30,6 @@ const GLOBAL_THIS: Realm = (function () {
 export function copy<Value>(value: Value, options?: Options): Value {
   // manually coalesced instead of default parameters for performance
   const isStrict = !!(options && options.isStrict);
-  const realm = (options && options.realm) || GLOBAL_THIS;
   const getObjectClone = isStrict ? getObjectCloneStrict : getObjectCloneLoose;
 
   /**
@@ -79,15 +54,15 @@ export function copy<Value>(value: Value, options?: Options): Value {
     const Constructor = prototype && prototype.constructor;
 
     // plain objects
-    if (!Constructor || Constructor === realm.Object) {
-      return getObjectClone(value, realm, handleCopy, cache);
+    if (!Constructor || Constructor === Object) {
+      return getObjectClone(value, handleCopy, cache);
     }
 
     // arrays
     if (isArray(value)) {
       // if strict, include non-standard properties
       if (isStrict) {
-        return getObjectCloneStrict(value, realm, handleCopy, cache);
+        return getObjectCloneStrict(value, handleCopy, cache);
       }
 
       const clone = new Constructor();
@@ -105,13 +80,15 @@ export function copy<Value>(value: Value, options?: Options): Value {
       return clone;
     }
 
+    const objectClass = toString.call(value);
+
     // dates
-    if (value instanceof realm.Date) {
+    if (objectClass === '[object Date]') {
       return new Constructor(value.getTime());
     }
 
     // regexps
-    if (value instanceof realm.RegExp) {
+    if (objectClass === '[object RegExp]') {
       const clone = new Constructor(
         value.source,
         value.flags || getRegExpFlags(value)
@@ -123,7 +100,7 @@ export function copy<Value>(value: Value, options?: Options): Value {
     }
 
     // maps
-    if (realm.Map && value instanceof realm.Map) {
+    if (objectClass === '[object Map]') {
       const clone = new Constructor();
 
       cache.set(value, clone);
@@ -136,7 +113,7 @@ export function copy<Value>(value: Value, options?: Options): Value {
     }
 
     // sets
-    if (realm.Set && value instanceof realm.Set) {
+    if (objectClass === '[object Set]') {
       const clone = new Constructor();
 
       cache.set(value, clone);
@@ -149,41 +126,38 @@ export function copy<Value>(value: Value, options?: Options): Value {
     }
 
     // blobs
-    if (realm.Blob && value instanceof realm.Blob) {
+    if (objectClass === '[object Blob]') {
       return value.slice(0, value.size, value.type);
     }
 
-    // buffers (node-only)
-    if (realm.Buffer && realm.Buffer.isBuffer(value)) {
-      const clone = realm.Buffer.allocUnsafe
-        ? realm.Buffer.allocUnsafe(value.length)
-        : new Constructor(value.length);
+    // dataviews
+    if (objectClass === '[object DataView]') {
+      const clone = new Constructor(value.buffer.slice(0));
 
       cache.set(value, clone);
-      value.copy(clone);
 
       return clone;
     }
 
-    // arraybuffers / dataviews
-    if (realm.ArrayBuffer) {
-      // dataviews
-      if (realm.ArrayBuffer.isView(value)) {
-        const clone = new Constructor(value.buffer.slice(0));
-
-        cache.set(value, clone);
-
-        return clone;
-      }
-
-      // arraybuffers
-      if (value instanceof realm.ArrayBuffer) {
-        const clone = value.slice(0);
+    // array buffers
+    if (
+      objectClass === '[object Float32Array]' ||
+      objectClass === '[object Float64Array]' ||
+      objectClass === '[object Int8Array]' ||
+      objectClass === '[object Int16Array]' ||
+      objectClass === '[object Int32Array]' ||
+      objectClass === '[object Uint8Array]' ||
+      objectClass === '[object Uint8ClampedArray]' ||
+      objectClass === '[object Uint16Array]' ||
+      objectClass === '[object Uint32Array]' ||
+      objectClass === '[object Uint64Array]' ||
+      objectClass === '[object ArrayBuffer]'
+    ) {
+      const clone = value.slice(0);
 
-        cache.set(value, clone);
+      cache.set(value, clone);
 
-        return clone;
-      }
+      return clone;
     }
 
     // if the value cannot / should not be cloned, don't
@@ -191,17 +165,17 @@ export function copy<Value>(value: Value, options?: Options): Value {
       // promise-like
       typeof value.then === 'function' ||
       // errors
-      value instanceof Error ||
+      objectClass === '[object Error]' ||
       // weakmaps
-      (realm.WeakMap && value instanceof realm.WeakMap) ||
+      objectClass === '[object WeakMap]' ||
       // weaksets
-      (realm.WeakSet && value instanceof realm.WeakSet)
+      objectClass === '[object WeakSet]'
     ) {
       return value;
     }
 
     // assume anything left is a custom constructor
-    return getObjectClone(value, realm, handleCopy, cache);
+    return getObjectClone(value, handleCopy, cache);
   };
 
   return handleCopy(value, createCache());
diff --git a/src/utils.ts b/src/utils.ts
index 960412e..dcb0168 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -10,7 +10,6 @@ export type InternalCopier = <Value = any>(value: Value, cache: Cache) => Value;
 
 export type ObjectCloner = <Value>(
   object: Value,
-  realm: Realm,
   handleCopy: InternalCopier,
   cache: Cache
 ) => Value;
@@ -65,7 +64,7 @@ export const createCache =
 /**
  * Get an empty version of the object with the same prototype it has.
  */
-export function getCleanClone(object: any, realm: Realm): any {
+export function getCleanClone(object: any): any {
   const prototype = object.__proto__ || getPrototypeOf(object);
 
   if (!prototype) {
@@ -74,8 +73,8 @@ export function getCleanClone(object: any, realm: Realm): any {
 
   const Constructor = prototype.constructor;
 
-  if (Constructor === realm.Object) {
-    return prototype === realm.Object.prototype ? {} : create(prototype);
+  if (Constructor === Object) {
+    return prototype === Object.prototype ? {} : create(prototype);
   }
 
   if (~toStringFunction.call(Constructor).indexOf('[native code]')) {
@@ -93,11 +92,10 @@ export function getCleanClone(object: any, realm: Realm): any {
  */
 export function getObjectCloneLoose(
   object: any,
-  realm: Realm,
   handleCopy: InternalCopier,
   cache: Cache
 ): any {
-  const clone: any = getCleanClone(object, realm);
+  const clone: any = getCleanClone(object);
 
   // set in the cache immediately to be able to reuse the object recursively
   cache.set(object, clone);
@@ -143,11 +141,10 @@ const getStrictProperties = SYMBOL_PROPERTIES
  */
 export function getObjectCloneStrict(
   object: any,
-  realm: Realm,
   handleCopy: InternalCopier,
   cache: Cache
 ): any {
-  const clone: any = getCleanClone(object, realm);
+  const clone: any = getCleanClone(object);
 
   // set in the cache immediately to be able to reuse the object recursively
   cache.set(object, clone);