diff --git a/fixtures/attribute-behavior/yarn.lock b/fixtures/attribute-behavior/yarn.lock
index 7529b7a098a..ef4b5ea106e 100644
--- a/fixtures/attribute-behavior/yarn.lock
+++ b/fixtures/attribute-behavior/yarn.lock
@@ -1361,8 +1361,9 @@ classnames@^2.2.3:
   resolved "https://registry.yarnpkg.com/classnames/-/classnames-2.2.5.tgz#fb3801d453467649ef3603c7d61a02bd129bde6d"
 
 clean-css@4.1.x:
-  version "4.1.7"
-  resolved "https://registry.yarnpkg.com/clean-css/-/clean-css-4.1.7.tgz#b9aea4f85679889cf3eae8b40349ec4ebdfdd032"
+  version "4.1.11"
+  resolved "https://registry.yarnpkg.com/clean-css/-/clean-css-4.1.11.tgz#2ecdf145aba38f54740f26cefd0ff3e03e125d6a"
+  integrity sha512-a3ZEe58u+LizPdSCHM0jIGeKu1hN+oqqXXc1i70mnV0x2Ox3/ho1pE6Y8HD6yhDts5lEQs028H9kutlihP77uQ==
   dependencies:
     source-map "0.5.x"