diff --git a/.mocharc.yml b/.mocharc.yml
index 36e79c2322..5e75d26389 100644
--- a/.mocharc.yml
+++ b/.mocharc.yml
@@ -2,4 +2,3 @@ throw-deprecation: true
 check-leaks: true
 require:
   - '@babel/register'
-  - '@babel/polyfill'
diff --git a/package.json b/package.json
index 1435ebe89f..875bd567e0 100644
--- a/package.json
+++ b/package.json
@@ -46,7 +46,6 @@
   "devDependencies": {
     "@babel/core": "7.8.3",
     "@babel/plugin-transform-flow-strip-types": "7.8.3",
-    "@babel/polyfill": "7.8.3",
     "@babel/preset-env": "7.8.3",
     "@babel/register": "7.8.3",
     "@typescript-eslint/eslint-plugin": "2.17.0",
diff --git a/yarn.lock b/yarn.lock
index c4498b340b..96c810174f 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -627,14 +627,6 @@
     "@babel/helper-create-regexp-features-plugin" "^7.8.3"
     "@babel/helper-plugin-utils" "^7.8.3"
 
-"@babel/polyfill@7.8.3":
-  version "7.8.3"
-  resolved "https://registry.yarnpkg.com/@babel/polyfill/-/polyfill-7.8.3.tgz#2333fc2144a542a7c07da39502ceeeb3abe4debd"
-  integrity sha512-0QEgn2zkCzqGIkSWWAEmvxD7e00Nm9asTtQvi7HdlYvMhjy/J38V/1Y9ode0zEJeIuxAI0uftiAzqc7nVeWUGg==
-  dependencies:
-    core-js "^2.6.5"
-    regenerator-runtime "^0.13.2"
-
 "@babel/preset-env@7.8.3":
   version "7.8.3"
   resolved "https://registry.yarnpkg.com/@babel/preset-env/-/preset-env-7.8.3.tgz#dc0fb2938f52bbddd79b3c861a4b3427dd3a6c54"
@@ -1291,11 +1283,6 @@ core-js-compat@^3.6.2:
     browserslist "^4.8.3"
     semver "7.0.0"
 
-core-js@^2.6.5:
-  version "2.6.11"
-  resolved "https://registry.yarnpkg.com/core-js/-/core-js-2.6.11.tgz#38831469f9922bded8ee21c9dc46985e0399308c"
-  integrity sha512-5wjnpaT/3dV+XB4borEsnAYQchn00XSgTAWKDkEqv+K8KevjbzmofK6hfJ9TZIlpj2N0xQpazy7PiRQiWHqzWg==
-
 core-util-is@1.0.2:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/core-util-is/-/core-util-is-1.0.2.tgz#b5fd54220aa2bc5ab57aab7140c940754503c1a7"
@@ -3316,11 +3303,6 @@ regenerate@^1.4.0:
   resolved "https://registry.yarnpkg.com/regenerate/-/regenerate-1.4.0.tgz#4a856ec4b56e4077c557589cae85e7a4c8869a11"
   integrity sha512-1G6jJVDWrt0rK99kBjvEtziZNCICAuvIPkSiUFIQxVP06RCVpq3dmDo2oi6ABpYaDYaTRr67BEhL8r1wgEZZKg==
 
-regenerator-runtime@^0.13.2:
-  version "0.13.3"
-  resolved "https://registry.yarnpkg.com/regenerator-runtime/-/regenerator-runtime-0.13.3.tgz#7cf6a77d8f5c6f60eb73c5fc1955b2ceb01e6bf5"
-  integrity sha512-naKIZz2GQ8JWh///G7L3X6LaQUAMp2lvb1rvwwsURe/VXwD6VMfr+/1NuNw3ag8v2kY1aQ/go5SNn79O9JU7yw==
-
 regenerator-transform@^0.14.0:
   version "0.14.1"
   resolved "https://registry.yarnpkg.com/regenerator-transform/-/regenerator-transform-0.14.1.tgz#3b2fce4e1ab7732c08f665dfdb314749c7ddd2fb"