diff --git a/omega-target-chromium-extension/.gitignore b/omega-target-chromium-extension/.gitignore
index 6654382..26addc4 100644
--- a/omega-target-chromium-extension/.gitignore
+++ b/omega-target-chromium-extension/.gitignore
@@ -1,5 +1,6 @@
 /index.js
 /omega_target_*.min.js
 
+/tmp
 /build
 /release.zip
diff --git a/omega-target-chromium-extension/Gruntfile.coffee b/omega-target-chromium-extension/Gruntfile.coffee
index 914195d..6c00819 100644
--- a/omega-target-chromium-extension/Gruntfile.coffee
+++ b/omega-target-chromium-extension/Gruntfile.coffee
@@ -1,3 +1,8 @@
 module.exports = (grunt) ->
   require('load-grunt-config')(grunt)
   require('./grunt-po2crx')(grunt)
+
+  grunt.registerTask 'chromium-manifest', ->
+    manifest = grunt.file.readJSON('overlay/manifest.json')
+    manifest.permissions = manifest.permissions.filter (p) -> p != 'downloads'
+    grunt.file.write('tmp/manifest.json', JSON.stringify(manifest))
diff --git a/omega-target-chromium-extension/grunt/aliases.coffee b/omega-target-chromium-extension/grunt/aliases.coffee
index 21938ba..c296b37 100644
--- a/omega-target-chromium-extension/grunt/aliases.coffee
+++ b/omega-target-chromium-extension/grunt/aliases.coffee
@@ -7,4 +7,4 @@ module.exports =
     'po2crx'
   ]
   test: ['mochaTest']
-  release: ['default', 'compress']
+  release: ['default', 'chromium-manifest', 'compress']
diff --git a/omega-target-chromium-extension/grunt/compress.coffee b/omega-target-chromium-extension/grunt/compress.coffee
index 6792332..7528a4b 100644
--- a/omega-target-chromium-extension/grunt/compress.coffee
+++ b/omega-target-chromium-extension/grunt/compress.coffee
@@ -3,7 +3,16 @@ module.exports =
     archive: './release.zip'
     mode: 'zip'
   build:
-    cwd: 'build'
-    src: ['**']
-    expand: true
-    filter: 'isFile'
+    files: [
+      {
+        cwd: 'build'
+        src: ['**', '!manifest.json']
+        expand: true
+        filter: 'isFile'
+      }
+      {
+        cwd: 'tmp/'
+        src: 'manifest.json'
+        expand: true
+      }
+    ]