diff --git a/2018-08/react-ts-refs/yarn.lock b/2018-08/react-ts-refs/yarn.lock
index 3b71c1a..7e17eaf 100644
--- a/2018-08/react-ts-refs/yarn.lock
+++ b/2018-08/react-ts-refs/yarn.lock
@@ -2320,8 +2320,8 @@ lodash.uniq@^4.5.0:
   resolved "https://registry.yarnpkg.com/lodash.uniq/-/lodash.uniq-4.5.0.tgz#d0225373aeb652adc1bc82e4945339a842754773"
 
 lodash@^4.17.4:
-  version "4.17.10"
-  resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.10.tgz#1b7793cf7259ea38fb3661d4d38b3260af8ae4e7"
+  version "4.17.21"
+  resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.21.tgz#679591c564c3bffaae8454cf0b3df370c3d6911c"
 
 log-symbols@^2.2.0:
   version "2.2.0"