diff --git a/package.json b/package.json
index 2d6fdb9..2567a21 100644
--- a/package.json
+++ b/package.json
@@ -17,7 +17,7 @@
     "gatsby-source-contentful": "^2.1.86",
     "gatsby-transformer-remark": "^2.1.12",
     "moment": "^2.22.2",
-    "prismjs": "^1.15.0",
+    "prismjs": "^1.21.0",
     "prop-types": "^15.6.2",
     "react": "^16.6.3",
     "react-dom": "^16.6.3",
diff --git a/yarn.lock b/yarn.lock
index 699bb27..2cdea55 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -2909,7 +2909,7 @@ ccount@^1.0.0, ccount@^1.0.3:
 
 chalk@1.1.3, chalk@^1.0.0, chalk@^1.1.3:
   version "1.1.3"
-  resolved "http://registry.npmjs.org/chalk/-/chalk-1.1.3.tgz#a8115c55e4a702fe4d150abd3872822a7e09fc98"
+  resolved "https://registry.npmjs.org/chalk/-/chalk-1.1.3.tgz#a8115c55e4a702fe4d150abd3872822a7e09fc98"
   dependencies:
     ansi-styles "^2.2.1"
     escape-string-regexp "^1.0.2"
@@ -10434,9 +10434,10 @@ pretty-error@^2.1.1:
     renderkid "^2.0.1"
     utila "~0.4"
 
-prismjs@^1.15.0:
-  version "1.15.0"
-  resolved "https://registry.yarnpkg.com/prismjs/-/prismjs-1.15.0.tgz#8801d332e472091ba8def94976c8877ad60398d9"
+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"