diff --git a/lib/config.js b/lib/config.js
index 0ac28fa..48cff46 100644
--- a/lib/config.js
+++ b/lib/config.js
@@ -1144,8 +1144,7 @@ function fromFloat(num, exp) {
   assert(typeof num === 'number' && isFinite(num));
   assert(Number.isSafeInteger(exp));
 
-  const str = num.toFixed(exp);
-
+  let str = num.toFixed(exp);
   let sign = 1;
 
   if (str.length > 0 && str[0] === '-') {
diff --git a/package.json b/package.json
index 40ef45c..95605ba 100644
--- a/package.json
+++ b/package.json
@@ -22,16 +22,16 @@
     "webpack": "webpack --config webpack.config.js"
   },
   "devDependencies": {
-    "babelify": "^7.3.0",
+    "babelify": "^8.0.0",
     "babel-core": "^6.26.0",
     "babel-loader": "^7.1.2",
     "babel-preset-env": "^1.6.1",
     "browserify": "^14.5.0",
-    "eslint": "^4.9.0",
+    "eslint": "^4.14.0",
     "mocha": "^4.0.1",
-    "uglifyjs-webpack-plugin": "^1.0.0-beta.3",
+    "uglifyjs-webpack-plugin": "^1.1.5",
     "uglify-es": "^3.1.3",
-    "webpack": "^3.8.1"
+    "webpack": "^3.10.0"
   },
   "engines": {
     "node": ">=7.6.0"