diff --git a/package-lock.json b/package-lock.json
index ec4d9f5f..31a046ea 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -41,7 +41,7 @@
         "optimist": "~0.4.0",
         "phantomjs": "^1.9.18",
         "sinon": "^1.10.3",
-        "uglify-js": "~2.2.3"
+        "uglify-js": "~3.17.4"
       }
     },
     "node_modules/@mapbox/sexagesimal": {
@@ -75,15 +75,6 @@
         "node": ">=0.3.0"
       }
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-    "node_modules/amdefine": {
-      "version": "1.0.1",
-      "resolved": "https://registry.npmjs.org/amdefine/-/amdefine-1.0.1.tgz",
-      "integrity": "sha1-SlKCrBZHKek2Gbz9OtFR+BfOkfU=",
-      "dev": true,
-      "engines": {
-        "node": ">=0.4.2"
-      }
-    },
     "node_modules/ansi-regex": {
       "version": "2.1.1",
       "resolved": "https://registry.npmjs.org/ansi-regex/-/ansi-regex-2.1.1.tgz",
@@ -2409,38 +2400,13 @@
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     },
     "node_modules/uglify-js": {
-      "version": "2.2.5",
-      "resolved": "https://registry.npmjs.org/uglify-js/-/uglify-js-2.2.5.tgz",
-      "integrity": "sha1-puAqcNg5eSuXgEiLe4sYTAlcmcc=",
+      "version": "3.17.4",
+      "resolved": "https://registry.npmjs.org/uglify-js/-/uglify-js-3.17.4.tgz",
+      "integrity": "sha512-T9q82TJI9e/C1TAxYvfb16xO120tMVFZrGA3f9/P4424DNu6ypK103y0GPFVa17yotwSyZW5iYXgjYHkGrJW/g==",
       "dev": true,
-      "dependencies": {
-        "optimist": "~0.3.5",
-        "source-map": "~0.1.7"
-      },
       "bin": {
         "uglifyjs": "bin/uglifyjs"
       },
-      "engines": {
-        "node": ">=0.4.0"
-      }
-    },
-    "node_modules/uglify-js/node_modules/optimist": {
-      "version": "0.3.7",
-      "resolved": "https://registry.npmjs.org/optimist/-/optimist-0.3.7.tgz",
-      "integrity": "sha1-yQlBrVnkJzMokjB00s8ufLxuwNk=",
-      "dev": true,
-      "dependencies": {
-        "wordwrap": "~0.0.2"
-      }
-    },
-    "node_modules/uglify-js/node_modules/source-map": {
-      "version": "0.1.43",
-      "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.1.43.tgz",
-      "integrity": "sha1-wkvBRspRfBRx9drL4lcbK3+eM0Y=",
-      "dev": true,
-      "dependencies": {
-        "amdefine": ">=0.0.4"
-      },
       "engines": {
         "node": ">=0.8.0"
       }
@@ -2575,12 +2541,6 @@
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       "dev": true
     },
-    "amdefine": {
-      "version": "1.0.1",
-      "resolved": "https://registry.npmjs.org/amdefine/-/amdefine-1.0.1.tgz",
-      "integrity": "sha1-SlKCrBZHKek2Gbz9OtFR+BfOkfU=",
-      "dev": true
-    },
     "ansi-regex": {
       "version": "2.1.1",
       "resolved": "https://registry.npmjs.org/ansi-regex/-/ansi-regex-2.1.1.tgz",
@@ -4517,34 +4477,10 @@
       "integrity": "sha1-hnrHTjhkGHsdPUfZlqeOxciDB3c="
     },
     "uglify-js": {
-      "version": "2.2.5",
-      "resolved": "https://registry.npmjs.org/uglify-js/-/uglify-js-2.2.5.tgz",
-      "integrity": "sha1-puAqcNg5eSuXgEiLe4sYTAlcmcc=",
-      "dev": true,
-      "requires": {
-        "optimist": "~0.3.5",
-        "source-map": "~0.1.7"
-      },
-      "dependencies": {
-        "optimist": {
-          "version": "0.3.7",
-          "resolved": "https://registry.npmjs.org/optimist/-/optimist-0.3.7.tgz",
-          "integrity": "sha1-yQlBrVnkJzMokjB00s8ufLxuwNk=",
-          "dev": true,
-          "requires": {
-            "wordwrap": "~0.0.2"
-          }
-        },
-        "source-map": {
-          "version": "0.1.43",
-          "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.1.43.tgz",
-          "integrity": "sha1-wkvBRspRfBRx9drL4lcbK3+eM0Y=",
-          "dev": true,
-          "requires": {
-            "amdefine": ">=0.0.4"
-          }
-        }
-      }
+      "version": "3.17.4",
+      "resolved": "https://registry.npmjs.org/uglify-js/-/uglify-js-3.17.4.tgz",
+      "integrity": "sha512-T9q82TJI9e/C1TAxYvfb16xO120tMVFZrGA3f9/P4424DNu6ypK103y0GPFVa17yotwSyZW5iYXgjYHkGrJW/g==",
+      "dev": true
     },
     "util": {
       "version": "0.10.3",
diff --git a/package.json b/package.json
index 89cf23cd..46fc25cb 100644
--- a/package.json
+++ b/package.json
@@ -13,7 +13,7 @@
     "optimist": "~0.4.0",
     "phantomjs": "^1.9.18",
     "sinon": "^1.10.3",
-    "uglify-js": "~2.2.3"
+    "uglify-js": "~3.17.4"
   },
   "scripts": {
     "test": "firefox test/index.html",