diff --git a/code/backend-express-runtypes-openapi/yarn.lock b/code/backend-express-runtypes-openapi/yarn.lock
index 2ac602e..7167930 100644
--- a/code/backend-express-runtypes-openapi/yarn.lock
+++ b/code/backend-express-runtypes-openapi/yarn.lock
@@ -3069,9 +3069,9 @@ postcss-values-parser@^6.0.2:
     quote-unquote "^1.0.0"
 
 postcss@^8.4.23:
-  version "8.4.28"
-  resolved "https://registry.yarnpkg.com/postcss/-/postcss-8.4.28.tgz#c6cc681ed00109072816e1557f889ef51cf950a5"
-  integrity sha512-Z7V5j0cq8oEKyejIKfpD8b4eBy9cwW2JWPk0+fB1HOAMsfHbnAXLLS+PfVWlzMSLQaWttKDt607I0XHmpE67Vw==
+  version "8.4.31"
+  resolved "https://registry.yarnpkg.com/postcss/-/postcss-8.4.31.tgz#92b451050a9f914da6755af352bdc0192508656d"
+  integrity sha512-PS08Iboia9mts/2ygV3eLpY5ghnUcfLV/EXTOW1E2qYxJKGGBUtNjN76FYHnMs36RmARn41bC0AZmn+rR0OVpQ==
   dependencies:
     nanoid "^3.3.6"
     picocolors "^1.0.0"