diff --git a/packages/babel-core/src/config/config-chain.js b/packages/babel-core/src/config/config-chain.js
index 60e062d3f8..81adcdff79 100644
--- a/packages/babel-core/src/config/config-chain.js
+++ b/packages/babel-core/src/config/config-chain.js
@@ -12,12 +12,7 @@ import {
 
 const debug = buildDebug("babel:config:config-chain");
 
-import {
-  findBabelrc,
-  findBabelignore,
-  loadConfig,
-  type ConfigFile,
-} from "./files";
+import { findRelativeConfig, loadConfig, type ConfigFile } from "./files";
 
 import { makeWeakCache, makeStrongCache } from "./caching";
 
@@ -108,7 +103,6 @@ const loadPresetOverridesEnvDescriptors = makeWeakCache(
  * Build a config chain for Babel's full root configuration.
  */
 export function buildRootChain(
-  cwd: string,
   opts: ValidatedOptions,
   context: ConfigContext,
 ): ConfigChain | null {
@@ -125,22 +119,15 @@ export function buildRootChain(
   // resolve all .babelrc files
   if (opts.babelrc !== false && context.filename !== null) {
     const filename = context.filename;
-    const babelignoreFile = findBabelignore(filename);
-    if (
-      babelignoreFile &&
-      shouldIgnore(
-        context,
-        babelignoreFile.ignore,
-        null,
-        babelignoreFile.dirname,
-      )
-    ) {
+
+    const { ignore, config } = findRelativeConfig(filename, context.envName);
+
+    if (ignore && shouldIgnore(context, ignore.ignore, null, ignore.dirname)) {
       return null;
     }
 
-    const babelrcFile = findBabelrc(filename, context.envName);
-    if (babelrcFile) {
-      const result = loadFileChain(babelrcFile, context);
+    if (config) {
+      const result = loadFileChain(config, context);
       if (!result) return null;
 
       mergeChain(fileChain, result);
diff --git a/packages/babel-core/src/config/files/configuration.js b/packages/babel-core/src/config/files/configuration.js
index 5617f3e473..73786b89fb 100644
--- a/packages/babel-core/src/config/files/configuration.js
+++ b/packages/babel-core/src/config/files/configuration.js
@@ -21,41 +21,58 @@ export type IgnoreFile = {
   ignore: Array<string>,
 };
 
+export type RelativeConfig = {
+  config: ConfigFile | null,
+  ignore: IgnoreFile | null,
+};
+
 const BABELRC_FILENAME = ".babelrc";
 const BABELRC_JS_FILENAME = ".babelrc.js";
 const PACKAGE_FILENAME = "package.json";
 const BABELIGNORE_FILENAME = ".babelignore";
 
-export function findBabelrc(
+export function findRelativeConfig(
   filepath: string,
   envName: string,
-): ConfigFile | null {
+): RelativeConfig {
+  let config = null;
+  let ignore = null;
+
   const dirname = path.dirname(filepath);
   let loc = dirname;
   while (true) {
-    const conf = [
-      BABELRC_FILENAME,
-      BABELRC_JS_FILENAME,
-      PACKAGE_FILENAME,
-    ].reduce((previousConfig: ConfigFile | null, name) => {
-      const filepath = path.join(loc, name);
-      const config = readConfig(filepath, envName);
+    if (!config) {
+      config = [BABELRC_FILENAME, BABELRC_JS_FILENAME, PACKAGE_FILENAME].reduce(
+        (previousConfig: ConfigFile | null, name) => {
+          const filepath = path.join(loc, name);
+          const config = readConfig(filepath, envName);
 
-      if (config && previousConfig) {
-        throw new Error(
-          `Multiple configuration files found. Please remove one:\n` +
-            ` - ${path.basename(previousConfig.filepath)}\n` +
-            ` - ${name}\n` +
-            `from ${loc}`,
-        );
+          if (config && previousConfig) {
+            throw new Error(
+              `Multiple configuration files found. Please remove one:\n` +
+                ` - ${path.basename(previousConfig.filepath)}\n` +
+                ` - ${name}\n` +
+                `from ${loc}`,
+            );
+          }
+
+          return config || previousConfig;
+        },
+        null,
+      );
+
+      if (config) {
+        debug("Found configuration %o from %o.", config.filepath, dirname);
       }
+    }
 
-      return config || previousConfig;
-    }, null);
+    if (!ignore) {
+      const ignoreLoc = path.join(loc, BABELIGNORE_FILENAME);
+      ignore = readIgnoreConfig(ignoreLoc);
 
-    if (conf) {
-      debug("Found configuration %o from %o.", conf.filepath, dirname);
-      return conf;
+      if (ignore) {
+        debug("Found ignore %o from %o.", ignore.filepath, dirname);
+      }
     }
 
     const nextLoc = path.dirname(loc);
@@ -63,27 +80,7 @@ export function findBabelrc(
     loc = nextLoc;
   }
 
-  return null;
-}
-
-export function findBabelignore(filepath: string): IgnoreFile | null {
-  const dirname = path.dirname(filepath);
-  let loc = dirname;
-  while (true) {
-    const ignoreLoc = path.join(loc, BABELIGNORE_FILENAME);
-    const ignore = readIgnoreConfig(ignoreLoc);
-
-    if (ignore) {
-      debug("Found ignore %o from %o.", ignore.filepath, dirname);
-      return ignore;
-    }
-
-    const nextLoc = path.dirname(loc);
-    if (loc === nextLoc) break;
-    loc = nextLoc;
-  }
-
-  return null;
+  return { config, ignore };
 }
 
 export function loadConfig(
@@ -106,7 +103,7 @@ export function loadConfig(
  * Read the given config file, returning the result. Returns null if no config was found, but will
  * throw if there are parsing errors while loading a config.
  */
-function readConfig(filepath, envName) {
+function readConfig(filepath, envName): ConfigFile | null {
   return path.extname(filepath) === ".js"
     ? readConfigJS(filepath, { envName })
     : readConfigFile(filepath);
diff --git a/packages/babel-core/src/config/files/index-browser.js b/packages/babel-core/src/config/files/index-browser.js
index bcd6b439a0..4e5cb5fe62 100644
--- a/packages/babel-core/src/config/files/index-browser.js
+++ b/packages/babel-core/src/config/files/index-browser.js
@@ -1,27 +1,14 @@
 // @flow
 
-export type ConfigFile = {
-  filepath: string,
-  dirname: string,
-  options: {},
-};
+import type { ConfigFile, IgnoreFile, RelativeConfig } from "./configuration";
 
-export type IgnoreFile = {
-  filepath: string,
-  dirname: string,
-  ignore: Array<string>,
-};
+export type { ConfigFile, IgnoreFile, RelativeConfig };
 
-export function findBabelrc(
+export function findRelativeConfig(
   filepath: string,
   envName: string, // eslint-disable-line no-unused-vars
-): ConfigFile | null {
-  return null;
-}
-
-// eslint-disable-next-line no-unused-vars
-export function findBabelignore(filepath: string): IgnoreFile | null {
-  return null;
+): RelativeConfig {
+  return { config: null, ignore: null };
 }
 
 export function loadConfig(name: string, dirname: string): ConfigFile {
diff --git a/packages/babel-core/src/config/index.js b/packages/babel-core/src/config/index.js
index 6a770e5aca..ef5d5c4a66 100644
--- a/packages/babel-core/src/config/index.js
+++ b/packages/babel-core/src/config/index.js
@@ -62,7 +62,7 @@ export default function loadConfig(inputOpts: mixed): ResolvedConfig | null {
     envName,
   };
 
-  const configChain = buildRootChain(absoluteCwd, args, context);
+  const configChain = buildRootChain(args, context);
   if (!configChain) return null;
 
   const optionDefaults = {};
diff --git a/packages/babel-core/src/config/validation/option-assertions.js b/packages/babel-core/src/config/validation/option-assertions.js
index c6330e7176..97b860f016 100644
--- a/packages/babel-core/src/config/validation/option-assertions.js
+++ b/packages/babel-core/src/config/validation/option-assertions.js
@@ -140,6 +140,8 @@ export function assertConfigApplicableTest(
   key: string,
   value: mixed,
 ): ConfigApplicableTest | void {
+  if (value === undefined) return value;
+
   if (Array.isArray(value)) {
     value.forEach((item, i) => {
       if (!checkValidTest(item)) {
diff --git a/packages/babel-core/src/parse.js b/packages/babel-core/src/parse.js
index 1a7e2231a3..94e7284520 100644
--- a/packages/babel-core/src/parse.js
+++ b/packages/babel-core/src/parse.js
@@ -1,6 +1,6 @@
 // @flow
 
-import loadConfig, { InputOptions } from "./config";
+import loadConfig, { type InputOptions } from "./config";
 import normalizeFile from "./transformation/normalize-file";
 import normalizeOptions from "./transformation/normalize-opts";
 
diff --git a/packages/babel-node/test/index.js b/packages/babel-node/test/index.js
index 6e48f0f2ab..4643475255 100644
--- a/packages/babel-node/test/index.js
+++ b/packages/babel-node/test/index.js
@@ -177,6 +177,16 @@ fs.readdirSync(fixtureLoc).forEach(function(binName) {
 
   const suiteLoc = path.join(fixtureLoc, binName);
   describe("bin/" + binName, function() {
+    let cwd;
+
+    beforeEach(() => {
+      cwd = process.cwd();
+    });
+
+    afterEach(() => {
+      process.chdir(cwd);
+    });
+
     fs.readdirSync(suiteLoc).forEach(function(testName) {
       if (testName[0] === ".") return;
 
diff --git a/packages/babel-preset-env/test/debug-fixtures.js b/packages/babel-preset-env/test/debug-fixtures.js
index 288407f8b3..4b4fcb2569 100644
--- a/packages/babel-preset-env/test/debug-fixtures.js
+++ b/packages/babel-preset-env/test/debug-fixtures.js
@@ -76,6 +76,16 @@ const buildTest = opts => {
 };
 
 describe("debug output", () => {
+  let cwd;
+
+  beforeEach(() => {
+    cwd = process.cwd();
+  });
+
+  afterEach(() => {
+    process.chdir(cwd);
+  });
+
   fs.readdirSync(fixtureLoc).forEach(testName => {
     if (testName.slice(0, 1) === ".") return;
     const testLoc = path.join(fixtureLoc, testName);
diff --git a/packages/babel-preset-env/test/fixtures/preset-options/browserslist-config/options.json b/packages/babel-preset-env/test/fixtures/preset-options/browserslist-config/options.json
index f048ce5e36..1545c51ee9 100644
--- a/packages/babel-preset-env/test/fixtures/preset-options/browserslist-config/options.json
+++ b/packages/babel-preset-env/test/fixtures/preset-options/browserslist-config/options.json
@@ -1,7 +1,7 @@
 {
   "presets": [
     ["../../../../lib", {
-      "configPath": "../fixtures/preset-options/browserslist-config",
+      "configPath": "packages/babel-preset-env/test/fixtures/preset-options/browserslist-config",
       "modules": false
     }]
   ]
diff --git a/packages/babel-preset-env/test/fixtures/preset-options/browserslist-package/options.json b/packages/babel-preset-env/test/fixtures/preset-options/browserslist-package/options.json
index 04183bdbd1..c10fd049d7 100644
--- a/packages/babel-preset-env/test/fixtures/preset-options/browserslist-package/options.json
+++ b/packages/babel-preset-env/test/fixtures/preset-options/browserslist-package/options.json
@@ -1,7 +1,7 @@
 {
   "presets": [
     ["../../../../lib", {
-      "configPath": "../fixtures/preset-options/browserslist-package",
+      "configPath": "packages/babel-preset-env/test/fixtures/preset-options/browserslist-package",
       "targets": {
         "chrome": 55
       },