diff --git a/package-lock.json b/package-lock.json
index e3a96ee9..42e60d91 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -13773,9 +13773,9 @@
       }
     },
     "prismjs": {
-      "version": "1.17.1",
-      "resolved": "https://registry.npmjs.org/prismjs/-/prismjs-1.17.1.tgz",
-      "integrity": "sha512-PrEDJAFdUGbOP6xK/UsfkC5ghJsPJviKgnQOoxaDbBjwc8op68Quupwt1DeAFoG8GImPhiKXAvvsH7wDSLsu1Q==",
+      "version": "1.21.0",
+      "resolved": "https://registry.npmjs.org/prismjs/-/prismjs-1.21.0.tgz",
+      "integrity": "sha512-uGdSIu1nk3kej2iZsLyDoJ7e9bnPzIgY0naW/HdknGj61zScaprVEVGHrPoXqI+M9sP0NDnTK2jpkvmldpuqDw==",
       "dev": true,
       "requires": {
         "clipboard": "^2.0.0"
diff --git a/package.json b/package.json
index 90c13409..4ad5cf2a 100644
--- a/package.json
+++ b/package.json
@@ -179,7 +179,7 @@
     "pdfobject": "~2.1.1",
     "plantuml-encoder": "^1.2.5",
     "power-assert": "~1.6.1",
-    "prismjs": "^1.17.1",
+    "prismjs": "^1.21.0",
     "raphael": "~2.2.8",
     "reveal.js": "~3.9.2",
     "script-loader": "~0.7.2",