diff --git a/.babelignore b/.babelignore
new file mode 100644
index 0000000000..1e2393e700
--- /dev/null
+++ b/.babelignore
@@ -0,0 +1,3 @@
+# Ensure babel-register won't compile fixtures, or try to recompile compiled code.
+packages/*/test/fixtures
+packages/*/lib
diff --git a/scripts/babel-register.js b/scripts/babel-register.js
deleted file mode 100644
index d70a3ff7ff..0000000000
--- a/scripts/babel-register.js
+++ /dev/null
@@ -1,10 +0,0 @@
-"use strict";
-
-const register = require("babel-register").default;
-
-register({
-  extensions: [".js"],
-  // Only js files in the test folder but not in the subfolder fixtures.
-  only: [/packages\/.+\/test\/(?!fixtures\/).+\.js$/],
-  compact: true,
-});
diff --git a/test/mocha.opts b/test/mocha.opts
index b4b84465b2..04d5d23a6b 100644
--- a/test/mocha.opts
+++ b/test/mocha.opts
@@ -1 +1 @@
---reporter dot --ui tdd --timeout 10000 --compilers js:./scripts/babel-register
+--reporter dot --ui tdd --timeout 10000 --compilers js:babel-register