diff --git a/gulpfile.js b/gulpfile.js
index 48863b18f..923af187f 100644
--- a/gulpfile.js
+++ b/gulpfile.js
@@ -1,13 +1,3 @@
-require('gulp')
-require('gulp-shell')
-require('gulp-concat')
-require('gulp-uglify')
-require('gulp-ext-replace')
-require('gulp-rename')
-require('gulp-istanbul')
-require('gulp-bump')
-require('gulp-tag-version')
-require('gulp-insert')
 var requireDir = require('require-dir')
 
 requireDir('./gulp/tasks')
diff --git a/package.json b/package.json
index 667457864..88f2b3ed4 100644
--- a/package.json
+++ b/package.json
@@ -109,7 +109,6 @@
     "gulp-rename": "~1.2.2",
     "gulp-shell": "^0.6.3",
     "gulp-tag-version": "^1.3.0",
-    "gulp-uglify": "~2.1.2",
     "gulp-util": "^3.0.8",
     "gulp-vartree": "^2.0.1",
     "hogan.js": "^3.0.2",
diff --git a/todo.md b/todo.md
index 3a0c65ffd..ed1a25522 100644
--- a/todo.md
+++ b/todo.md
@@ -13,4 +13,4 @@
     - babel-plugin-transform-remove-strict-mode
         - need to remove it after upgrading to d3 v4
 - use headless chrome provided by karma-chrome-launcher
-- https://github.com/karma-runner/karma-chrome-launcher
+    - https://github.com/karma-runner/karma-chrome-launcher
diff --git a/yarn.lock b/yarn.lock
index da81fa6df..b1be86c3d 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -3564,19 +3564,6 @@ gulp-tag-version@^1.3.0:
     gulp-util "~2.2.14"
     map-stream "~0.1.0"
 
-gulp-uglify@~2.1.2:
-  version "2.1.2"
-  resolved "https://registry.yarnpkg.com/gulp-uglify/-/gulp-uglify-2.1.2.tgz#6db85b1d0ee63d18058592b658649d65c2ec4541"
-  dependencies:
-    gulplog "^1.0.0"
-    has-gulplog "^0.1.0"
-    lodash "^4.13.1"
-    make-error-cause "^1.1.1"
-    through2 "^2.0.0"
-    uglify-js "~2.8.10"
-    uglify-save-license "^0.4.1"
-    vinyl-sourcemaps-apply "^0.2.0"
-
 gulp-util@^3.0.0, gulp-util@^3.0.1, gulp-util@^3.0.2, gulp-util@^3.0.4, gulp-util@^3.0.6, gulp-util@^3.0.7, gulp-util@^3.0.8, gulp-util@~3.0.1, gulp-util@~3.0.4, gulp-util@~3.0.6:
   version "3.0.8"
   resolved "https://registry.yarnpkg.com/gulp-util/-/gulp-util-3.0.8.tgz#0054e1e744502e27c04c187c3ecc505dd54bbb4f"
@@ -5047,7 +5034,7 @@ lodash@^3.10.0, lodash@^3.3.1, lodash@^3.7.0, lodash@^3.8.0:
   version "3.10.1"
   resolved "https://registry.yarnpkg.com/lodash/-/lodash-3.10.1.tgz#5bf45e8e49ba4189e17d482789dfd15bd140b7b6"
 
-lodash@^4.0.0, lodash@^4.11.1, lodash@^4.12.0, lodash@^4.13.1, lodash@^4.14.0, lodash@^4.15.0, lodash@^4.17.4, lodash@^4.2.0, lodash@^4.3.0, lodash@^4.5, lodash@^4.5.0:
+lodash@^4.0.0, lodash@^4.11.1, lodash@^4.12.0, lodash@^4.14.0, lodash@^4.15.0, lodash@^4.17.4, lodash@^4.2.0, lodash@^4.3.0, lodash@^4.5, lodash@^4.5.0:
   version "4.17.4"
   resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.4.tgz#78203a4d1c328ae1d86dca6460e369b57f4055ae"
 
@@ -5100,16 +5087,6 @@ lru-cache@^4.0.0:
     pseudomap "^1.0.1"
     yallist "^2.0.0"
 
-make-error-cause@^1.1.1:
-  version "1.2.2"
-  resolved "https://registry.yarnpkg.com/make-error-cause/-/make-error-cause-1.2.2.tgz#df0388fcd0b37816dff0a5fb8108939777dcbc9d"
-  dependencies:
-    make-error "^1.2.0"
-
-make-error@^1.2.0:
-  version "1.2.3"
-  resolved "https://registry.yarnpkg.com/make-error/-/make-error-1.2.3.tgz#6c4402df732e0977ac6faf754a5074b3d2b1d19d"
-
 map-cache@^0.2.0:
   version "0.2.2"
   resolved "https://registry.yarnpkg.com/map-cache/-/map-cache-0.2.2.tgz#c32abd0bd6525d9b051645bb4f26ac5dc98a0dbf"
@@ -7608,7 +7585,7 @@ uc.micro@^1.0.1:
   version "1.0.3"
   resolved "https://registry.yarnpkg.com/uc.micro/-/uc.micro-1.0.3.tgz#7ed50d5e0f9a9fb0a573379259f2a77458d50192"
 
-uglify-js@^2.6, uglify-js@^2.7.0, uglify-js@^2.8.5, uglify-js@~2.8.10:
+uglify-js@^2.6, uglify-js@^2.7.0, uglify-js@^2.8.5:
   version "2.8.22"
   resolved "https://registry.yarnpkg.com/uglify-js/-/uglify-js-2.8.22.tgz#d54934778a8da14903fa29a326fb24c0ab51a1a0"
   dependencies:
@@ -7617,10 +7594,6 @@ uglify-js@^2.6, uglify-js@^2.7.0, uglify-js@^2.8.5, uglify-js@~2.8.10:
   optionalDependencies:
     uglify-to-browserify "~1.0.0"
 
-uglify-save-license@^0.4.1:
-  version "0.4.1"
-  resolved "https://registry.yarnpkg.com/uglify-save-license/-/uglify-save-license-0.4.1.tgz#95726c17cc6fd171c3617e3bf4d8d82aa8c4cce1"
-
 uglify-to-browserify@~1.0.0:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/uglify-to-browserify/-/uglify-to-browserify-1.0.2.tgz#6e0924d6bda6b5afe349e39a6d632850a0f882b7"