diff --git a/themes/learn4/yarn.lock b/themes/learn4/yarn.lock
index 184c80b2..9d812d94 100644
--- a/themes/learn4/yarn.lock
+++ b/themes/learn4/yarn.lock
@@ -3873,14 +3873,10 @@ lodash.templatesettings@^3.0.0:
     lodash._reinterpolate "^3.0.0"
     lodash.escape "^3.0.0"
 
-lodash@^4.0.0, lodash@~4.17.4:
-  version "4.17.10"
-  resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.10.tgz#1b7793cf7259ea38fb3661d4d38b3260af8ae4e7"
-
-lodash@^4.17.11, lodash@^4.17.4, lodash@^4.2.0:
-  version "4.17.11"
-  resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.11.tgz#b39ea6229ef607ecd89e2c8df12536891cac9b8d"
-  integrity sha512-cQKh8igo5QUhZ7lg38DYWAxMvjSAKG0A8wGSVimP07SIUEK2UO+arSRKbRZWtelMtN5V0Hkwh5ryOto/SshYIg==
+lodash@^4.0.0, lodash@^4.17.11, lodash@^4.17.4, lodash@^4.2.0, lodash@~4.17.4:
+  version "4.17.21"
+  resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.21.tgz#679591c564c3bffaae8454cf0b3df370c3d6911c"
+  integrity sha512-v2kDEe57lecTulaDIuNTPy3Ry4gLGJ6Z1O3vE1krgXZNrsQ+LFTGHVxVjcXPs17LhbZVGedAJv8XZ1tvj5FvSg==
 
 loose-envify@^1.0.0:
   version "1.4.0"