diff --git a/BUILD.bazel b/BUILD.bazel
index 9e2e0ae584..596b2934d6 100644
--- a/BUILD.bazel
+++ b/BUILD.bazel
@@ -24,7 +24,7 @@ filegroup(
         "//packages/zone.js/bundles:zone-testing.umd.js",
         "//packages/zone.js/bundles:task-tracking.umd.js",
         "//:test-events.js",
-        "//:third_party/shims_for_IE.js",
+        "//:third_party/shims_for_internal_tests.js",
         # Including systemjs because it defines `__eval`, which produces correct stack traces.
         "@npm//:node_modules/systemjs/dist/system.src.js",
         "@npm//:node_modules/reflect-metadata/Reflect.js",
diff --git a/karma-js.conf.js b/karma-js.conf.js
index 956b2860f8..1652ca4ba2 100644
--- a/karma-js.conf.js
+++ b/karma-js.conf.js
@@ -50,7 +50,7 @@ module.exports = function(config) {
 
       // Including systemjs because it defines `__eval`, which produces correct stack traces.
       'test-events.js',
-      'third_party/shims_for_IE.js',
+      'third_party/shims_for_internal_tests.js',
       'node_modules/systemjs/dist/system.src.js',
 
       // Serve polyfills necessary for testing the `elements` package.
diff --git a/packages/router/karma.conf.js b/packages/router/karma.conf.js
index 2b5cb9e95a..17ba88a9da 100644
--- a/packages/router/karma.conf.js
+++ b/packages/router/karma.conf.js
@@ -28,7 +28,7 @@ module.exports = function(config) {
       // Polyfills.
       'node_modules/core-js/client/core.js',
       'node_modules/reflect-metadata/Reflect.js',
-      'third_party/shims_for_IE.js',
+      'third_party/shims_for_internal_tests.js',
 
       // System.js for module loading
       'node_modules/systemjs/dist/system-polyfills.js',
diff --git a/third_party/shims_for_IE.js b/third_party/shims_for_internal_tests.js
similarity index 99%
rename from third_party/shims_for_IE.js
rename to third_party/shims_for_internal_tests.js
index 1bce7a77ad..974e98845c 100644
--- a/third_party/shims_for_IE.js
+++ b/third_party/shims_for_internal_tests.js
@@ -1,4 +1,4 @@
-// This file is used for internal testing with Karma only, it should not be used in real applications.
+// IMPORTANT: this file is used for internal testing with Karma only, it **must not** be used in real applications.
 
 // Intl (all Safari, all Android)
 /*! @source https://github.com/andyearnshaw/Intl.js */