diff --git a/packages/babel-register/README.md b/packages/babel-register/README.md
index 214e6ffde5..a72e2fb003 100644
--- a/packages/babel-register/README.md
+++ b/packages/babel-register/README.md
@@ -68,10 +68,7 @@ require("@babel/register")({
   extensions: [".es6", ".es", ".jsx", ".js", ".mjs"],
 
   // Setting this to false will disable the cache.
-  cache: true,
-
-  // Specify the version of babel-core used for transformation. (Optional)
-  babel: require('@babel/core')
+  cache: true
 });
 ```
 
diff --git a/packages/babel-register/src/node.js b/packages/babel-register/src/node.js
index a0ea770b08..a20514f2a1 100644
--- a/packages/babel-register/src/node.js
+++ b/packages/babel-register/src/node.js
@@ -2,7 +2,7 @@ import deepClone from "lodash/cloneDeep";
 import sourceMapSupport from "source-map-support";
 import * as registerCache from "./cache";
 import escapeRegExp from "lodash/escapeRegExp";
-import * as babelCore from "@babel/core";
+import * as babel from "@babel/core";
 import { OptionManager, DEFAULT_EXTENSIONS } from "@babel/core";
 import { addHook } from "pirates";
 import fs from "fs";
@@ -10,7 +10,6 @@ import path from "path";
 
 const maps = {};
 const transformOpts = {};
-let babel = null;
 let piratesRevert = null;
 
 function installSourceMapSupport() {
@@ -101,9 +100,6 @@ register({
 export default function register(opts?: Object = {}) {
   // Clone to avoid mutating the arguments object with the 'delete's below.
   opts = Object.assign({}, opts);
-
-  babel = opts.babel ? opts.babel : babelCore;
-
   if (opts.extensions) hookExtensions(opts.extensions);
 
   if (opts.cache === false && cache) {
@@ -114,7 +110,6 @@ export default function register(opts?: Object = {}) {
     cache = registerCache.get();
   }
 
-  delete opts.babel;
   delete opts.extensions;
   delete opts.cache;
 
diff --git a/packages/babel-register/test/index.js b/packages/babel-register/test/index.js
index 8ccff83b26..a41f299e19 100644
--- a/packages/babel-register/test/index.js
+++ b/packages/babel-register/test/index.js
@@ -103,36 +103,4 @@ describe("@babel/register", function() {
     chai.expect((gen_error = require(GEN_ERROR))).to.be.ok;
     chai.expect(gen_error()).to.match(/gen_error\.js:2:86/);
   });
-
-  it("uses custom babel when requested", () => {
-    setupRegister({
-      babel: {
-        transform() {
-          return { code: "module.exports = 'hello';" };
-        },
-        getEnv() {
-          return {};
-        },
-        version: "custom",
-      },
-    });
-
-    chai.expect(require(DATA_ES2015)).to.equal("hello");
-  });
-
-  it("resets babel on subsequent register calls", () => {
-    function crash() {
-      throw new Error("shouldn't be called");
-    }
-
-    setupRegister({
-      babel: {
-        transform: crash,
-        getEnv: crash,
-      },
-    });
-    setupRegister();
-
-    chai.expect(require(DATA_ES2015)).to.be.ok;
-  });
 });