diff --git a/Gruntfile.coffee b/Gruntfile.coffee
index dac7ba6d0..ba1d5a8c3 100755
--- a/Gruntfile.coffee
+++ b/Gruntfile.coffee
@@ -1,4 +1,6 @@
+path = require 'path'
 crx = require 'crx'
+JSZip = require 'jszip'
 
 module.exports = (grunt) ->
   grunt.util.linefeed = '\n'
@@ -234,19 +236,6 @@ module.exports = (grunt) ->
         ]
         tasks: 'build'
 
-    compress:
-      crx:
-        options:
-          archive: 'testbuilds/<%= pkg.name %><%= pkg.meta.suffix[pkg.channel] %>.crx.zip'
-          level: 9
-          pretty: true
-        expand:  true
-        flatten: true
-        src: 'testbuilds/crx<%= pkg.meta.suffix[pkg.channel] %>/*'
-        dest: '/'
-        date: '<%= pkg.meta.date %>'
-        mode: parseInt('644', 8)
-
     clean:
       builds: 'builds'
       testbuilds: 'testbuilds'
@@ -329,7 +318,7 @@ module.exports = (grunt) ->
   grunt.registerTask 'build-crx-channel', [
     'concat:crx'
     'copy:crx'
-    'compress:crx'
+    'zip-crx'
   ]
 
   grunt.registerTask 'build-crx', [
@@ -348,6 +337,17 @@ module.exports = (grunt) ->
     'clean:tmpcrx'
   ]
 
+  grunt.registerTask 'zip-crx', 'Pack CRX contents in ZIP file', ->
+    pkg = grunt.config 'pkg'
+    zip = new JSZip()
+    for file in grunt.file.expand "testbuilds/crx#{pkg.meta.suffix[pkg.channel]}/*"
+      zip.file path.basename(file), grunt.file.read(file, {encoding: null}), {date: new Date(pkg.meta.date)}
+    output = zip.generate
+      type: 'nodebuffer'
+      compression: 'DEFLATE'
+      compressionOptions: {level: 9}
+    grunt.file.write "testbuilds/#{pkg.name}#{pkg.meta.suffix[pkg.channel]}.crx.zip", output
+
   grunt.registerTask 'sign-channel', 'Sign CRX package', (channel) ->
     done = @async()
     pkg = grunt.config 'pkg'
diff --git a/npm-shrinkwrap.json b/npm-shrinkwrap.json
index 46cc83a2c..686d074f5 100644
--- a/npm-shrinkwrap.json
+++ b/npm-shrinkwrap.json
@@ -465,198 +465,6 @@
         }
       }
     },
-    "grunt-contrib-compress": {
-      "version": "0.13.0",
-      "resolved": "https://registry.npmjs.org/grunt-contrib-compress/-/grunt-contrib-compress-0.13.0.tgz",
-      "dependencies": {
-        "archiver": {
-          "version": "0.13.1",
-          "resolved": "https://registry.npmjs.org/archiver/-/archiver-0.13.1.tgz",
-          "dependencies": {
-            "async": {
-              "version": "0.9.0",
-              "resolved": "https://registry.npmjs.org/async/-/async-0.9.0.tgz"
-            },
-            "buffer-crc32": {
-              "version": "0.2.5",
-              "resolved": "https://registry.npmjs.org/buffer-crc32/-/buffer-crc32-0.2.5.tgz"
-            },
-            "glob": {
-              "version": "4.3.5",
-              "resolved": "https://registry.npmjs.org/glob/-/glob-4.3.5.tgz",
-              "dependencies": {
-                "inflight": {
-                  "version": "1.0.4",
-                  "resolved": "https://registry.npmjs.org/inflight/-/inflight-1.0.4.tgz",
-                  "dependencies": {
-                    "wrappy": {
-                      "version": "1.0.1",
-                      "resolved": "https://registry.npmjs.org/wrappy/-/wrappy-1.0.1.tgz"
-                    }
-                  }
-                },
-                "inherits": {
-                  "version": "2.0.1",
-                  "resolved": "https://registry.npmjs.org/inherits/-/inherits-2.0.1.tgz"
-                },
-                "minimatch": {
-                  "version": "2.0.1",
-                  "resolved": "https://registry.npmjs.org/minimatch/-/minimatch-2.0.1.tgz",
-                  "dependencies": {
-                    "brace-expansion": {
-                      "version": "1.1.0",
-                      "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-1.1.0.tgz",
-                      "dependencies": {
-                        "balanced-match": {
-                          "version": "0.2.0",
-                          "resolved": "https://registry.npmjs.org/balanced-match/-/balanced-match-0.2.0.tgz"
-                        },
-                        "concat-map": {
-                          "version": "0.0.1",
-                          "resolved": "https://registry.npmjs.org/concat-map/-/concat-map-0.0.1.tgz"
-                        }
-                      }
-                    }
-                  }
-                },
-                "once": {
-                  "version": "1.3.1",
-                  "resolved": "https://registry.npmjs.org/once/-/once-1.3.1.tgz",
-                  "dependencies": {
-                    "wrappy": {
-                      "version": "1.0.1",
-                      "resolved": "https://registry.npmjs.org/wrappy/-/wrappy-1.0.1.tgz"
-                    }
-                  }
-                }
-              }
-            },
-            "lazystream": {
-              "version": "0.1.0",
-              "resolved": "https://registry.npmjs.org/lazystream/-/lazystream-0.1.0.tgz"
-            },
-            "lodash": {
-              "version": "2.4.1",
-              "resolved": "https://registry.npmjs.org/lodash/-/lodash-2.4.1.tgz"
-            },
-            "readable-stream": {
-              "version": "1.0.33",
-              "resolved": "https://registry.npmjs.org/readable-stream/-/readable-stream-1.0.33.tgz",
-              "dependencies": {
-                "core-util-is": {
-                  "version": "1.0.1",
-                  "resolved": "https://registry.npmjs.org/core-util-is/-/core-util-is-1.0.1.tgz"
-                },
-                "inherits": {
-                  "version": "2.0.1",
-                  "resolved": "https://registry.npmjs.org/inherits/-/inherits-2.0.1.tgz"
-                },
-                "isarray": {
-                  "version": "0.0.1",
-                  "resolved": "https://registry.npmjs.org/isarray/-/isarray-0.0.1.tgz"
-                },
-                "string_decoder": {
-                  "version": "0.10.31",
-                  "resolved": "https://registry.npmjs.org/string_decoder/-/string_decoder-0.10.31.tgz"
-                }
-              }
-            },
-            "tar-stream": {
-              "version": "1.1.2",
-              "resolved": "https://registry.npmjs.org/tar-stream/-/tar-stream-1.1.2.tgz",
-              "dependencies": {
-                "bl": {
-                  "version": "0.9.3",
-                  "resolved": "https://registry.npmjs.org/bl/-/bl-0.9.3.tgz"
-                },
-                "end-of-stream": {
-                  "version": "1.1.0",
-                  "resolved": "https://registry.npmjs.org/end-of-stream/-/end-of-stream-1.1.0.tgz",
-                  "dependencies": {
-                    "once": {
-                      "version": "1.3.1",
-                      "resolved": "https://registry.npmjs.org/once/-/once-1.3.1.tgz",
-                      "dependencies": {
-                        "wrappy": {
-                          "version": "1.0.1",
-                          "resolved": "https://registry.npmjs.org/wrappy/-/wrappy-1.0.1.tgz"
-                        }
-                      }
-                    }
-                  }
-                },
-                "xtend": {
-                  "version": "4.0.0",
-                  "resolved": "https://registry.npmjs.org/xtend/-/xtend-4.0.0.tgz"
-                }
-              }
-            },
-            "zip-stream": {
-              "version": "0.5.0",
-              "resolved": "https://registry.npmjs.org/zip-stream/-/zip-stream-0.5.0.tgz",
-              "dependencies": {
-                "compress-commons": {
-                  "version": "0.2.0",
-                  "resolved": "https://registry.npmjs.org/compress-commons/-/compress-commons-0.2.0.tgz",
-                  "dependencies": {
-                    "crc32-stream": {
-                      "version": "0.3.1",
-                      "resolved": "https://registry.npmjs.org/crc32-stream/-/crc32-stream-0.3.1.tgz"
-                    },
-                    "node-int64": {
-                      "version": "0.3.3",
-                      "resolved": "https://registry.npmjs.org/node-int64/-/node-int64-0.3.3.tgz"
-                    }
-                  }
-                }
-              }
-            }
-          }
-        },
-        "chalk": {
-          "version": "0.5.1",
-          "resolved": "https://registry.npmjs.org/chalk/-/chalk-0.5.1.tgz",
-          "dependencies": {
-            "ansi-styles": {
-              "version": "1.1.0",
-              "resolved": "https://registry.npmjs.org/ansi-styles/-/ansi-styles-1.1.0.tgz"
-            },
-            "escape-string-regexp": {
-              "version": "1.0.2",
-              "resolved": "https://registry.npmjs.org/escape-string-regexp/-/escape-string-regexp-1.0.2.tgz"
-            },
-            "has-ansi": {
-              "version": "0.1.0",
-              "resolved": "https://registry.npmjs.org/has-ansi/-/has-ansi-0.1.0.tgz",
-              "dependencies": {
-                "ansi-regex": {
-                  "version": "0.2.1",
-                  "resolved": "https://registry.npmjs.org/ansi-regex/-/ansi-regex-0.2.1.tgz"
-                }
-              }
-            },
-            "strip-ansi": {
-              "version": "0.3.0",
-              "resolved": "https://registry.npmjs.org/strip-ansi/-/strip-ansi-0.3.0.tgz",
-              "dependencies": {
-                "ansi-regex": {
-                  "version": "0.2.1",
-                  "resolved": "https://registry.npmjs.org/ansi-regex/-/ansi-regex-0.2.1.tgz"
-                }
-              }
-            },
-            "supports-color": {
-              "version": "0.2.0",
-              "resolved": "https://registry.npmjs.org/supports-color/-/supports-color-0.2.0.tgz"
-            }
-          }
-        },
-        "prettysize": {
-          "version": "0.0.3",
-          "resolved": "https://registry.npmjs.org/prettysize/-/prettysize-0.0.3.tgz"
-        }
-      }
-    },
     "grunt-contrib-concat": {
       "version": "0.5.1",
       "resolved": "https://registry.npmjs.org/grunt-contrib-concat/-/grunt-contrib-concat-0.5.1.tgz",
@@ -1081,6 +889,16 @@
         }
       }
     },
+    "jszip": {
+      "version": "2.5.0",
+      "resolved": "https://registry.npmjs.org/jszip/-/jszip-2.5.0.tgz",
+      "dependencies": {
+        "pako": {
+          "version": "0.2.6",
+          "resolved": "https://registry.npmjs.org/pako/-/pako-0.2.6.tgz"
+        }
+      }
+    },
     "load-grunt-tasks": {
       "version": "3.1.0",
       "resolved": "https://registry.npmjs.org/load-grunt-tasks/-/load-grunt-tasks-3.1.0.tgz",
diff --git a/package.json b/package.json
index f63b265c9..6c6beb57f 100755
--- a/package.json
+++ b/package.json
@@ -49,7 +49,6 @@
     "grunt-concurrent": "^1.0.0",
     "grunt-contrib-clean": "^0.6.0",
     "grunt-contrib-coffee": "^0.13.0",
-    "grunt-contrib-compress": "^0.13.0",
     "grunt-contrib-concat": "^0.5.1",
     "grunt-contrib-copy": "^0.8.0",
     "grunt-contrib-jshint": "^0.11.1",
@@ -57,6 +56,7 @@
     "grunt-markdown": "^0.7.0",
     "grunt-shell": "^1.1.2",
     "grunt-webstore-upload": "^0.8.2",
+    "jszip": "^2.5.0",
     "load-grunt-tasks": "^3.1.0",
     "npm-shrinkwrap": "^5.3.0"
   },