diff --git a/package-lock.json b/package-lock.json
index f4635ab..af49bb2 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -402,9 +402,9 @@
       }
     },
     "lodash": {
-      "version": "3.10.1",
-      "resolved": "https://registry.npmjs.org/lodash/-/lodash-3.10.1.tgz",
-      "integrity": "sha1-W/Rejkm6QYnhfUgnid/RW9FAt7Y="
+      "version": "4.17.21",
+      "resolved": "https://registry.npmjs.org/lodash/-/lodash-4.17.21.tgz",
+      "integrity": "sha512-v2kDEe57lecTulaDIuNTPy3Ry4gLGJ6Z1O3vE1krgXZNrsQ+LFTGHVxVjcXPs17LhbZVGedAJv8XZ1tvj5FvSg=="
     },
     "lodash.omit": {
       "version": "4.5.0",
diff --git a/package.json b/package.json
index 2be828a..a9277f6 100644
--- a/package.json
+++ b/package.json
@@ -6,7 +6,7 @@
     "ejs": "^2.3.4",
     "katex": "^0.5.1",
     "http-server": "^0.8.5",
-    "lodash": "^3.10.1",
+    "lodash": "^4.17.21",
     "metalsmith": "^2.1.0",
     "metalsmith-collections": "^0.7.0",
     "metalsmith-drafts": "0.0.1",