diff --git a/package-lock.json b/package-lock.json
index b3cc137..c095f7a 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -185,12 +185,6 @@
       "integrity": "sha1-BDP0TYCWgP3rYO0mDxsMJi6CpAs=",
       "dev": true
     },
-    "commander": {
-      "version": "2.13.0",
-      "resolved": "https://registry.npmjs.org/commander/-/commander-2.13.0.tgz",
-      "integrity": "sha512-MVuS359B+YzaWqjCL/c+22gfryv+mCBPHAv3zyVI2GN8EY6IRP8VwtasXn8jyyhvvq84R4ImN1OKRtcbIasjYA==",
-      "dev": true
-    },
     "concat-map": {
       "version": "0.0.1",
       "resolved": "https://registry.npmjs.org/concat-map/-/concat-map-0.0.1.tgz",
@@ -1084,12 +1078,6 @@
       "integrity": "sha1-VusCfWW00tzmyy4tMsTUr8nh1wc=",
       "dev": true
     },
-    "source-map": {
-      "version": "0.6.1",
-      "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.6.1.tgz",
-      "integrity": "sha512-UjgapumWlbMhkBgzT7Ykc5YXUT46F0iKu8SGXq0bcwP5dz/h0Plj6enJqjz1Zbq2l5WaqYnrVbwWOWMyF3F47g==",
-      "dev": true
-    },
     "spawn-sync": {
       "version": "1.0.15",
       "resolved": "https://registry.npmjs.org/spawn-sync/-/spawn-sync-1.0.15.tgz",
@@ -1215,14 +1203,10 @@
       "dev": true
     },
     "uglify-js": {
-      "version": "3.3.8",
-      "resolved": "https://registry.npmjs.org/uglify-js/-/uglify-js-3.3.8.tgz",
-      "integrity": "sha512-X0jAGtpSZRtd4RhbVNuGHyjZNa/h2MrVkKrR3Ew5iL2MJw6d7FmBke+fhVCALWySv1ygHnjjROG1KI1FAPvddw==",
-      "dev": true,
-      "requires": {
-        "commander": "2.13.0",
-        "source-map": "0.6.1"
-      }
+      "version": "3.13.4",
+      "resolved": "https://registry.npmjs.org/uglify-js/-/uglify-js-3.13.4.tgz",
+      "integrity": "sha512-kv7fCkIXyQIilD5/yQy8O+uagsYIOt5cZvs890W40/e/rvjMSzJw81o9Bg0tkURxzZBROtDQhW2LFjOGoK3RZw==",
+      "dev": true
     },
     "union": {
       "version": "0.4.6",
diff --git a/package.json b/package.json
index 998593d..531c06d 100644
--- a/package.json
+++ b/package.json
@@ -16,7 +16,7 @@
     "license": "ISC",
     "devDependencies": {
         "http-server": "^0.10.0",
-        "uglify-js": "^3.3.8",
+        "uglify-js": "^3.13.4",
         "workbox-cli": "^2.1.2"
     }
 }