diff --git a/2018-05/ts-react-default-props/yarn.lock b/2018-05/ts-react-default-props/yarn.lock
index be94d8e..c15fc68 100644
--- a/2018-05/ts-react-default-props/yarn.lock
+++ b/2018-05/ts-react-default-props/yarn.lock
@@ -1129,8 +1129,8 @@ css-url-regex@^1.1.0:
   resolved "https://registry.yarnpkg.com/css-url-regex/-/css-url-regex-1.1.0.tgz#83834230cc9f74c457de59eebd1543feeb83b7ec"
 
 css-what@2.1:
-  version "2.1.0"
-  resolved "https://registry.yarnpkg.com/css-what/-/css-what-2.1.0.tgz#9467d032c38cfaefb9f2d79501253062f87fa1bd"
+  version "2.1.3"
+  resolved "https://registry.yarnpkg.com/css-what/-/css-what-2.1.3.tgz#a6d7604573365fe74686c3f311c56513d88285f2"
 
 cssnano@^3.10.0, cssnano@^3.4.0:
   version "3.10.0"