diff --git a/packages/babel-cli/src/babel/dir.js b/packages/babel-cli/src/babel/dir.js
index 7356574504b7..bbdcf4ac3286 100644
--- a/packages/babel-cli/src/babel/dir.js
+++ b/packages/babel-cli/src/babel/dir.js
@@ -1,6 +1,5 @@
 // @flow
 
-import defaults from "lodash/defaults";
 import debounce from "lodash/debounce";
 import { sync as makeDirSync } from "make-dir";
 import slash from "slash";
@@ -48,15 +47,10 @@ export default async function ({
     const dest = getDest(relative, base);
 
     try {
-      const res = await util.compile(
-        src,
-        defaults(
-          {
-            sourceFileName: slash(path.relative(dest + "/..", src)),
-          },
-          babelOptions,
-        ),
-      );
+      const res = await util.compile(src, {
+        ...babelOptions,
+        sourceFileName: slash(path.relative(dest + "/..", src)),
+      });
 
       if (!res) return FILE_TYPE.IGNORED;
 
diff --git a/packages/babel-cli/src/babel/file.js b/packages/babel-cli/src/babel/file.js
index 89e780acd908..a6927157d524 100644
--- a/packages/babel-cli/src/babel/file.js
+++ b/packages/babel-cli/src/babel/file.js
@@ -1,7 +1,6 @@
 // @flow
 
 import convertSourceMap from "convert-source-map";
-import defaults from "lodash/defaults";
 import sourceMap from "source-map";
 import slash from "slash";
 import { sync as makeDirSync } from "make-dir";
@@ -127,16 +126,10 @@ export default async function ({
   async function stdin(): Promise<void> {
     const code = await readStdin();
 
-    const res = await util.transform(
-      cliOptions.filename,
-      code,
-      defaults(
-        {
-          sourceFileName: "stdin",
-        },
-        babelOptions,
-      ),
-    );
+    const res = await util.transform(cliOptions.filename, code, {
+      ...babelOptions,
+      sourceFileName: "stdin",
+    });
 
     output([res]);
   }
@@ -177,22 +170,17 @@ export default async function ({
         sourceFilename = slash(sourceFilename);
 
         try {
-          return await util.compile(
-            filename,
-            defaults(
-              {
-                sourceFileName: sourceFilename,
-                // Since we're compiling everything to be merged together,
-                // "inline" applies to the final output file, but not to the individual
-                // files being concatenated.
-                sourceMaps:
-                  babelOptions.sourceMaps === "inline"
-                    ? true
-                    : babelOptions.sourceMaps,
-              },
-              babelOptions,
-            ),
-          );
+          return await util.compile(filename, {
+            ...babelOptions,
+            sourceFileName: sourceFilename,
+            // Since we're compiling everything to be merged together,
+            // "inline" applies to the final output file, but not to the individual
+            // files being concatenated.
+            sourceMaps:
+              babelOptions.sourceMaps === "inline"
+                ? true
+                : babelOptions.sourceMaps,
+          });
         } catch (err) {
           if (!cliOptions.watch) {
             throw err;
diff --git a/packages/babel-cli/test/fixtures/babel/env - SHOW_CONFIG_FOR with multiple files-windows/stdout.txt b/packages/babel-cli/test/fixtures/babel/env - SHOW_CONFIG_FOR with multiple files-windows/stdout.txt
index 303ac82e7f34..b9a7167fab33 100644
--- a/packages/babel-cli/test/fixtures/babel/env - SHOW_CONFIG_FOR with multiple files-windows/stdout.txt	
+++ b/packages/babel-cli/test/fixtures/babel/env - SHOW_CONFIG_FOR with multiple files-windows/stdout.txt	
@@ -15,7 +15,6 @@ config <CWD>/.babelrc
 
 programmatic options from @babel/cli
 {
-  "sourceFileName": "src/foo.js",
   "presets": [
     "<ROOTDIR>//packages//babel-preset-react"
   ],
@@ -24,6 +23,7 @@ programmatic options from @babel/cli
     "<ROOTDIR>//packages//babel-plugin-transform-strict-mode",
     "<ROOTDIR>//packages//babel-plugin-transform-modules-commonjs"
   ],
+  "sourceFileName": "src/foo.js",
   "caller": {
     "name": "@babel/cli"
   },
diff --git a/packages/babel-cli/test/fixtures/babel/env - SHOW_CONFIG_FOR with multiple files/stdout.txt b/packages/babel-cli/test/fixtures/babel/env - SHOW_CONFIG_FOR with multiple files/stdout.txt
index 0f982f0e98c4..1a70215b9c34 100644
--- a/packages/babel-cli/test/fixtures/babel/env - SHOW_CONFIG_FOR with multiple files/stdout.txt	
+++ b/packages/babel-cli/test/fixtures/babel/env - SHOW_CONFIG_FOR with multiple files/stdout.txt	
@@ -15,7 +15,6 @@ config <CWD>/.babelrc
 
 programmatic options from @babel/cli
 {
-  "sourceFileName": "src/foo.js",
   "presets": [
     "<ROOTDIR>/packages/babel-preset-react"
   ],
@@ -24,6 +23,7 @@ programmatic options from @babel/cli
     "<ROOTDIR>/packages/babel-plugin-transform-strict-mode",
     "<ROOTDIR>/packages/babel-plugin-transform-modules-commonjs"
   ],
+  "sourceFileName": "src/foo.js",
   "caller": {
     "name": "@babel/cli"
   },
diff --git a/packages/babel-cli/test/fixtures/babel/env - SHOW_CONFIG_FOR-windows/stdout.txt b/packages/babel-cli/test/fixtures/babel/env - SHOW_CONFIG_FOR-windows/stdout.txt
index 5d5860f58f82..3a3d6a02c7c3 100644
--- a/packages/babel-cli/test/fixtures/babel/env - SHOW_CONFIG_FOR-windows/stdout.txt	
+++ b/packages/babel-cli/test/fixtures/babel/env - SHOW_CONFIG_FOR-windows/stdout.txt	
@@ -15,7 +15,6 @@ config <CWD>/.babelrc
 
 programmatic options from @babel/cli
 {
-  "sourceFileName": "../src/foo.js",
   "presets": [
     "<ROOTDIR>//packages//babel-preset-react"
   ],
@@ -24,6 +23,7 @@ programmatic options from @babel/cli
     "<ROOTDIR>//packages//babel-plugin-transform-strict-mode",
     "<ROOTDIR>//packages//babel-plugin-transform-modules-commonjs"
   ],
+  "sourceFileName": "../src/foo.js",
   "caller": {
     "name": "@babel/cli"
   },
diff --git a/packages/babel-cli/test/fixtures/babel/env - SHOW_CONFIG_FOR/stdout.txt b/packages/babel-cli/test/fixtures/babel/env - SHOW_CONFIG_FOR/stdout.txt
index b648f9d8bb48..fed8218c93ee 100644
--- a/packages/babel-cli/test/fixtures/babel/env - SHOW_CONFIG_FOR/stdout.txt	
+++ b/packages/babel-cli/test/fixtures/babel/env - SHOW_CONFIG_FOR/stdout.txt	
@@ -110,7 +110,6 @@ config <CWD>/.babelrc
 
 programmatic options from @babel/cli
 {
-  "sourceFileName": "./src/index.js",
   "presets": [
     "<ROOTDIR>/packages/babel-preset-react"
   ],
@@ -120,6 +119,7 @@ programmatic options from @babel/cli
     "<ROOTDIR>/packages/babel-plugin-transform-modules-commonjs"
   ],
   "configFile": "./my-config.js",
+  "sourceFileName": "./src/index.js",
   "caller": {
     "name": "@babel/cli"
   },
diff --git a/packages/babel-helper-transform-fixture-test-runner/src/index.js b/packages/babel-helper-transform-fixture-test-runner/src/index.js
index 75187153e130..30dc091523e1 100644
--- a/packages/babel-helper-transform-fixture-test-runner/src/index.js
+++ b/packages/babel-helper-transform-fixture-test-runner/src/index.js
@@ -4,7 +4,6 @@ import { buildExternalHelpers } from "@babel/core";
 import getFixtures from "@babel/helper-fixtures";
 import sourceMap from "source-map";
 import { codeFrameColumns } from "@babel/code-frame";
-import defaults from "lodash/defaults";
 import escapeRegExp from "lodash/escapeRegExp";
 import * as helpers from "./helpers";
 import merge from "lodash/merge";
@@ -442,9 +441,11 @@ export default function (
               run(task);
             }
 
-            defaults(task.options, {
-              sourceMap: !!(task.sourceMappings || task.sourceMap),
-            });
+            if ("sourceMap" in task.options === false) {
+              task.options.sourceMap = !!(
+                task.sourceMappings || task.sourceMap
+              );
+            }
 
             Object.assign(task.options, taskOpts);
 
diff --git a/packages/babel-traverse/src/scope/index.js b/packages/babel-traverse/src/scope/index.js
index 321db204ccc4..c5ca4a4a544b 100644
--- a/packages/babel-traverse/src/scope/index.js
+++ b/packages/babel-traverse/src/scope/index.js
@@ -1,7 +1,6 @@
 import Renamer from "./lib/renamer";
 import type NodePath from "../path";
 import traverse from "../index";
-import defaults from "lodash/defaults";
 import Binding from "./binding";
 import globals from "globals";
 import * as t from "@babel/types";
@@ -956,7 +955,11 @@ export default class Scope {
 
     let scope = this;
     do {
-      defaults(ids, scope.bindings);
+      for (const key of Object.keys(scope.bindings)) {
+        if (key in ids === false) {
+          ids[key] = scope.bindings[key];
+        }
+      }
       scope = scope.parent;
     } while (scope);