diff --git a/core/test/utils/fixtures/themes/casper/yarn.lock b/core/test/utils/fixtures/themes/casper/yarn.lock
index 6bbeafde572..14319c99ecb 100644
--- a/core/test/utils/fixtures/themes/casper/yarn.lock
+++ b/core/test/utils/fixtures/themes/casper/yarn.lock
@@ -1050,7 +1050,7 @@ esutils@^2.0.2:
 
 event-stream@^3.1.7:
   version "3.3.4"
-  resolved "http://registry.npmjs.org/event-stream/-/event-stream-3.3.4.tgz#4ab4c9a0f5a54db9338b4c34d86bfce8f4b35571"
+  resolved "https://registry.npmjs.org/event-stream/-/event-stream-3.3.4.tgz#4ab4c9a0f5a54db9338b4c34d86bfce8f4b35571"
   dependencies:
     duplexer "~0.1.1"
     from "~0"
@@ -3790,8 +3790,8 @@ systemjs@^0.19.46:
     when "^3.7.5"
 
 tar-fs@^1.13.0:
-  version "1.16.0"
-  resolved "https://registry.yarnpkg.com/tar-fs/-/tar-fs-1.16.0.tgz#e877a25acbcc51d8c790da1c57c9cf439817b896"
+  version "1.16.6"
+  resolved "https://registry.yarnpkg.com/tar-fs/-/tar-fs-1.16.6.tgz#b9be1854fe2c88af488a2edcc570be965e9750bd"
   dependencies:
     chownr "^1.0.1"
     mkdirp "^0.5.1"