diff --git a/changelogs/unreleased/enable-auto-cancelling-by-default.yml b/changelogs/unreleased/enable-auto-cancelling-by-default.yml
new file mode 100644
index 00000000000..8b1659bf38b
--- /dev/null
+++ b/changelogs/unreleased/enable-auto-cancelling-by-default.yml
@@ -0,0 +1,4 @@
+---
+title: Enable cancelling non-HEAD pending pipelines by default for all projects
+merge_request: 11023
+author:
diff --git a/db/migrate/20170502065653_make_auto_cancel_pending_pipelines_on_by_default.rb b/db/migrate/20170502065653_make_auto_cancel_pending_pipelines_on_by_default.rb
new file mode 100644
index 00000000000..03bf626a08a
--- /dev/null
+++ b/db/migrate/20170502065653_make_auto_cancel_pending_pipelines_on_by_default.rb
@@ -0,0 +1,13 @@
+class MakeAutoCancelPendingPipelinesOnByDefault < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  def up
+    change_column_default(:projects, :auto_cancel_pending_pipelines, 1)
+  end
+
+  def down
+    change_column_default(:projects, :auto_cancel_pending_pipelines, 0)
+  end
+end
diff --git a/db/post_migrate/20170502070007_enable_auto_cancel_pending_pipelines_for_all.rb b/db/post_migrate/20170502070007_enable_auto_cancel_pending_pipelines_for_all.rb
new file mode 100644
index 00000000000..a19b73fc114
--- /dev/null
+++ b/db/post_migrate/20170502070007_enable_auto_cancel_pending_pipelines_for_all.rb
@@ -0,0 +1,15 @@
+class EnableAutoCancelPendingPipelinesForAll < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  disable_ddl_transaction!
+
+  DOWNTIME = false
+
+  def up
+    update_column_in_batches(:projects, :auto_cancel_pending_pipelines, 1)
+  end
+
+  def down
+    # Nothing we can do!
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 4aaf3642173..a683521c84b 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -988,7 +988,7 @@ ActiveRecord::Schema.define(version: 20170508190732) do
     t.text "description_html"
     t.boolean "only_allow_merge_if_all_discussions_are_resolved"
     t.boolean "printing_merge_request_link_enabled", default: true, null: false
-    t.integer "auto_cancel_pending_pipelines", default: 0, null: false
+    t.integer "auto_cancel_pending_pipelines", default: 1, null: false
     t.string "import_jid"
     t.integer "cached_markdown_version"
     t.datetime "last_repository_updated_at"
diff --git a/spec/workers/post_receive_spec.rb b/spec/workers/post_receive_spec.rb
index 3289c2df1fb..f4bc63bcc6a 100644
--- a/spec/workers/post_receive_spec.rb
+++ b/spec/workers/post_receive_spec.rb
@@ -4,13 +4,16 @@ describe PostReceive do
   let(:changes) { "123456 789012 refs/heads/tést\n654321 210987 refs/tags/tag" }
   let(:wrongly_encoded_changes) { changes.encode("ISO-8859-1").force_encoding("UTF-8") }
   let(:base64_changes) { Base64.encode64(wrongly_encoded_changes) }
-  let(:project) { create(:project, :repository) }
   let(:project_identifier) { "project-#{project.id}" }
   let(:key) { create(:key, user: project.owner) }
   let(:key_id) { key.shell_id }
 
+  let(:project) do
+    create(:project, :repository, auto_cancel_pending_pipelines: 'disabled')
+  end
+
   context "as a sidekiq worker" do
-    it "reponds to #perform" do
+    it "responds to #perform" do
       expect(described_class.new).to respond_to(:perform)
     end
   end