diff --git a/package.json b/package.json
index 076dbb9..c11bffe 100644
--- a/package.json
+++ b/package.json
@@ -33,7 +33,7 @@
     "gatsby-transformer-sharp": "^2.3.19",
     "gitalk": "^1.6.2",
     "netlify-cms-app": "^2.11.32",
-    "prismjs": "^1.19.0",
+    "prismjs": "^1.21.0",
     "react": "^16.12.0",
     "react-dom": "^16.12.0",
     "react-helmet": "^5.2.1",
diff --git a/yarn.lock b/yarn.lock
index 0acf124..349c9c6 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -11609,10 +11609,10 @@ pretty-format@^3.5.1:
   resolved "https://registry.yarnpkg.com/pretty-format/-/pretty-format-3.8.0.tgz#bfbed56d5e9a776645f4b1ff7aa1a3ac4fa3c385"
   integrity sha1-v77VbV6ad2ZF9LH/eqGjrE+jw4U=
 
-prismjs@^1.19.0:
-  version "1.19.0"
-  resolved "https://registry.yarnpkg.com/prismjs/-/prismjs-1.19.0.tgz#713afbd45c3baca4b321569f2df39e17e729d4dc"
-  integrity sha512-IVFtbW9mCWm9eOIaEkNyo2Vl4NnEifis2GQ7/MLRG5TQe6t+4Sj9J5QWI9i3v+SS43uZBlCAOn+zYTVYQcPXJw==
+prismjs@^1.21.0:
+  version "1.21.0"
+  resolved "https://registry.yarnpkg.com/prismjs/-/prismjs-1.21.0.tgz#36c086ec36b45319ec4218ee164c110f9fc015a3"
+  integrity sha512-uGdSIu1nk3kej2iZsLyDoJ7e9bnPzIgY0naW/HdknGj61zScaprVEVGHrPoXqI+M9sP0NDnTK2jpkvmldpuqDw==
   optionalDependencies:
     clipboard "^2.0.0"