diff --git a/README.md b/README.md
index ee3c1ab7d..65368f5fe 100644
--- a/README.md
+++ b/README.md
@@ -74,6 +74,7 @@ Please review [Contributing guidelines](./CONTRIBUTING.md) and [Code components]
 - [Frequently Asked Questions](./docs/faq.md)
 - [Using in browser](#using-in-browser)
   - [Content Security Policy](./docs/security.md#content-security-policy)
+- [Using in ES5 environment](#using-in-es5-environment)
 - [Command line interface](#command-line-interface)
 - [API reference](./docs/api.md)
   - [Methods](./docs/api.md#ajv-constructor-and-methods)
@@ -307,6 +308,19 @@ The browser bundle is available on [cdnjs](https://cdnjs.com/libraries/ajv).
 
 **Please note**: some frameworks, e.g. Dojo, may redefine global require in a way that is not compatible with CommonJS module format. In this case Ajv bundle has to be loaded before the framework and then you can use global `ajv` (see issue [#234](https://github.com/ajv-validator/ajv/issues/234)).
 
+## Using in ES5 environment
+
+You need to:
+
+- recompile Typescript to ES5 target - it is set to 2018 in the bundled compiled code.
+- generate ES5 validation code:
+
+```javascript
+const ajv = new Ajv({code: {es5: true}})
+```
+
+See [Advanced options](https://github.com/ajv-validator/ajv/blob/master/docs/api.md#advanced-options).
+
 ## Command line interface
 
 CLI is available as a separate npm package [ajv-cli](https://github.com/ajv-validator/ajv-cli). It supports:
diff --git a/lib/vocabularies/applicator/oneOf.ts b/lib/vocabularies/applicator/oneOf.ts
index f34c2dc97..268c2376e 100644
--- a/lib/vocabularies/applicator/oneOf.ts
+++ b/lib/vocabularies/applicator/oneOf.ts
@@ -9,7 +9,11 @@ import {_, Name} from "../../compile/codegen"
 import {alwaysValidSchema} from "../../compile/util"
 import {SchemaCxt} from "../../compile"
 
-export type OneOfError = ErrorObject<"oneOf", {passingSchemas: [number, number] | null}, AnySchema[]>
+export type OneOfError = ErrorObject<
+  "oneOf",
+  {passingSchemas: [number, number] | null},
+  AnySchema[]
+>
 
 const error: KeywordErrorDefinition = {
   message: "should match exactly one schema in oneOf",