diff --git a/app/controllers/groups_controller.rb b/app/controllers/groups_controller.rb
index bd6b44bdbbceacb03df7fec8f39cc42bbf441c1f..e8d9d9fb34431c18ac0de1ff796d4c0367c4f76d 100644
--- a/app/controllers/groups_controller.rb
+++ b/app/controllers/groups_controller.rb
@@ -133,7 +133,7 @@ class GroupsController < Groups::ApplicationController
   end
 
   def group_params
-    params.require(:group).permit(:name, :description, :path, :avatar, :public)
+    params.require(:group).permit(:name, :description, :path, :avatar, :public, :share_with_group_lock)
   end
 
   def load_events
diff --git a/app/models/project.rb b/app/models/project.rb
index 56865459724fecc39b0ddbd1c5573a69acc78e34..40f8c4c83da5bff5d858a70a56b080c3530dc91c 100644
--- a/app/models/project.rb
+++ b/app/models/project.rb
@@ -881,8 +881,7 @@ class Project < ActiveRecord::Base
   end
 
   def allowed_to_share_with_group?
-    # TODO: replace with logic
-    true
+    !namespace.share_with_group_lock
   end
 
   def ci_commit(sha)
diff --git a/app/views/groups/edit.html.haml b/app/views/groups/edit.html.haml
index 3430f56a9c98890681fba9d0974beab6ebe7d471..83936d39b16fd3cc11b24d621f189b5bce6f0757 100644
--- a/app/views/groups/edit.html.haml
+++ b/app/views/groups/edit.html.haml
@@ -23,6 +23,15 @@
             %hr
             = link_to 'Remove avatar', group_avatar_path(@group.to_param), data: { confirm: "Group avatar will be removed. Are you sure?"}, method: :delete, class: "btn btn-remove btn-sm remove-avatar"
 
+      .form-group
+        %hr
+        = f.label :share_with_group_lock, class: 'control-label' do
+          Share with group lock
+        .col-sm-10
+          .checkbox
+            = f.check_box :share_with_group_lock
+            %span.descr Prevent sharing a project with another group within this group
+
       .form-actions
         = f.submit 'Save group', class: "btn btn-save"
 
diff --git a/db/migrate/20150930110012_add_group_share_lock.rb b/db/migrate/20150930110012_add_group_share_lock.rb
new file mode 100644
index 0000000000000000000000000000000000000000..78d1a4538f250870e944f4a6fc559687dc917428
--- /dev/null
+++ b/db/migrate/20150930110012_add_group_share_lock.rb
@@ -0,0 +1,5 @@
+class AddGroupShareLock < ActiveRecord::Migration
+  def change
+    add_column :namespaces, :share_with_group_lock, :boolean, default: false
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 89e8c9e67b0685994aff9fc95fd0d84a63788221..20dbb4f5a3eb7f6b4417e4a5fbf5a7462e0e8a5f 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -568,14 +568,15 @@ ActiveRecord::Schema.define(version: 20160309140734) do
   add_index "milestones", ["title"], name: "index_milestones_on_title", using: :btree
 
   create_table "namespaces", force: :cascade do |t|
-    t.string   "name",                     null: false
-    t.string   "path",                     null: false
+    t.string   "name",                                  null: false
+    t.string   "path",                                  null: false
     t.integer  "owner_id"
     t.datetime "created_at"
     t.datetime "updated_at"
     t.string   "type"
-    t.string   "description", default: "", null: false
+    t.string   "description",           default: "",    null: false
     t.string   "avatar"
+    t.boolean  "share_with_group_lock", default: false
   end
 
   add_index "namespaces", ["created_at", "id"], name: "index_namespaces_on_created_at_and_id", using: :btree