diff --git a/package-lock.json b/package-lock.json
index 25d2037..1ed5975 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -195,9 +195,9 @@
             "dev": true
         },
         "duplexer": {
-            "version": "0.1.1",
-            "resolved": "https://registry.npmjs.org/duplexer/-/duplexer-0.1.1.tgz",
-            "integrity": "sha1-rOb/gIwc5mtX0ev5eXessCM0z8E=",
+            "version": "0.1.2",
+            "resolved": "https://registry.npmjs.org/duplexer/-/duplexer-0.1.2.tgz",
+            "integrity": "sha512-jtD6YG370ZCIi/9GTaJKQxWTZD045+4R4hTk/x1UyoqadyJ9x9CgSi1RlVDQF8U2sxLLSnFkCaMihqljHIWgMg==",
             "dev": true
         },
         "error": {
@@ -422,15 +422,23 @@
             "dev": true
         },
         "grunt-contrib-uglify": {
-            "version": "4.0.1",
-            "resolved": "https://registry.npmjs.org/grunt-contrib-uglify/-/grunt-contrib-uglify-4.0.1.tgz",
-            "integrity": "sha512-dwf8/+4uW1+7pH72WButOEnzErPGmtUvc8p08B0eQS/6ON0WdeQu0+WFeafaPTbbY1GqtS25lsHWaDeiTQNWPg==",
+            "version": "5.0.1",
+            "resolved": "https://registry.npmjs.org/grunt-contrib-uglify/-/grunt-contrib-uglify-5.0.1.tgz",
+            "integrity": "sha512-T/aXZ4WIpAtoswZqb6HROKg7uq9QbKwl+lUuOwK4eoFj3tFv9/a/oMyd3/qvetV29Pbf8P1YYda1gDwZppr60A==",
             "dev": true,
             "requires": {
                 "chalk": "^2.4.1",
                 "maxmin": "^2.1.0",
-                "uglify-js": "^3.5.0",
+                "uglify-js": "^3.13.3",
                 "uri-path": "^1.0.0"
+            },
+            "dependencies": {
+                "uglify-js": {
+                    "version": "3.13.3",
+                    "resolved": "https://registry.npmjs.org/uglify-js/-/uglify-js-3.13.3.tgz",
+                    "integrity": "sha512-otIc7O9LyxpUcQoXzj2hL4LPWKklO6LJWoJUzNa8A17Xgi4fOeDC8FBDOLHnC/Slo1CQgsZMcM6as0M76BZaig==",
+                    "dev": true
+                }
             }
         },
         "grunt-contrib-watch": {
diff --git a/package.json b/package.json
index 6d493f5..a2fe622 100644
--- a/package.json
+++ b/package.json
@@ -10,7 +10,7 @@
     "devDependencies": {
         "grunt": "^1.0",
         "grunt-check-modules": "^1.0.0",
-        "grunt-contrib-uglify": "^4.0",
+        "grunt-contrib-uglify": "^5.0",
         "grunt-contrib-watch": "^1.1",
         "grunt-jasmine-nodejs": "^1.6",
         "jasmine": "^3.4.0",