diff --git a/db/post_migrate/20180424151928_fill_file_store.rb.rb b/db/post_migrate/20180424151928_fill_file_store.rb
similarity index 100%
rename from db/post_migrate/20180424151928_fill_file_store.rb.rb
rename to db/post_migrate/20180424151928_fill_file_store.rb
diff --git a/lib/gitlab/background_migration/fill_file_store_job_artifact.rb b/lib/gitlab/background_migration/fill_file_store_job_artifact.rb
index dfd1e7191d2..508e0102911 100644
--- a/lib/gitlab/background_migration/fill_file_store_job_artifact.rb
+++ b/lib/gitlab/background_migration/fill_file_store_job_artifact.rb
@@ -10,8 +10,8 @@ module Gitlab
       end
 
       def perform(start_id, stop_id)
-        FillFileStoreJobArtifact::JobArtifact
-          .where('file_store = NULL')
+        Gitlab::BackgroundMigration::FillFileStoreJobArtifact::JobArtifact
+          .where('file_store is NULL')
           .where(id: (start_id..stop_id))
           .update_all(file_store: 1)
       end
diff --git a/lib/gitlab/background_migration/fill_file_store_lfs_object.rb b/lib/gitlab/background_migration/fill_file_store_lfs_object.rb
index d423bcfba95..5cd926b8121 100644
--- a/lib/gitlab/background_migration/fill_file_store_lfs_object.rb
+++ b/lib/gitlab/background_migration/fill_file_store_lfs_object.rb
@@ -10,8 +10,8 @@ module Gitlab
       end
 
       def perform(start_id, stop_id)
-        FillFileStoreLfsObject::LfsObject
-          .where('file_store = NULL')
+        Gitlab::BackgroundMigration::FillFileStoreLfsObject::LfsObject
+          .where('file_store is NULL')
           .where(id: (start_id..stop_id))
           .update_all(file_store: 1)
       end
diff --git a/lib/gitlab/background_migration/fill_file_store_upload.rb b/lib/gitlab/background_migration/fill_file_store_upload.rb
index 14f4c667ed8..203c3cea09f 100644
--- a/lib/gitlab/background_migration/fill_file_store_upload.rb
+++ b/lib/gitlab/background_migration/fill_file_store_upload.rb
@@ -11,8 +11,8 @@ module Gitlab
       end
 
       def perform(start_id, stop_id)
-        FillFileStoreUpload::Upload
-          .where('store = NULL')
+        Gitlab::BackgroundMigration::FillFileStoreUpload::Upload
+          .where('store is NULL')
           .where(id: (start_id..stop_id))
           .update_all(store: 1)
       end
diff --git a/spec/migrations/fill_file_store_spec.rb b/spec/migrations/fill_file_store_spec.rb
new file mode 100644
index 00000000000..5ff7aa56ce2
--- /dev/null
+++ b/spec/migrations/fill_file_store_spec.rb
@@ -0,0 +1,43 @@
+require 'spec_helper'
+require Rails.root.join('db', 'post_migrate', '20180424151928_fill_file_store')
+
+describe FillFileStore, :migration do
+  let(:namespaces) { table(:namespaces) }
+  let(:projects) { table(:projects) }
+  let(:builds) { table(:ci_builds) }
+  let(:job_artifacts) { table(:ci_job_artifacts) }
+  let(:lfs_objects) { table(:lfs_objects) }
+  let(:uploads) { table(:uploads) }
+
+  before do
+    namespaces.create!(id: 123, name: 'gitlab1', path: 'gitlab1')
+    projects.create!(id: 123, name: 'gitlab1', path: 'gitlab1', namespace_id: 123)
+    builds.create!(id: 1)
+
+    ##
+    # Create rows that have nullfied `file_store` column
+    job_artifacts.create!(project_id: 123, job_id: 1, file_type: 1, file_store: nil)
+    lfs_objects.create!(oid: 123, size: 10, file: 'file_name', file_store: nil)
+    uploads.create!(size: 10, path: 'path', uploader: 'uploader', mount_point: 'file_name', store: nil)
+  end
+
+  it 'correctly migrates nullified file_store/store column' do
+    expect(job_artifacts.where(file_store: nil).count).to eq(1)
+    expect(lfs_objects.where(file_store: nil).count).to eq(1)
+    expect(uploads.where(store: nil).count).to eq(1)
+
+    expect(job_artifacts.where(file_store: 1).count).to eq(0)
+    expect(lfs_objects.where(file_store: 1).count).to eq(0)
+    expect(uploads.where(store: 1).count).to eq(0)
+
+    migrate!
+
+    expect(job_artifacts.where(file_store: nil).count).to eq(0)
+    expect(lfs_objects.where(file_store: nil).count).to eq(0)
+    expect(uploads.where(store: nil).count).to eq(0)
+
+    expect(job_artifacts.where(file_store: 1).count).to eq(1)
+    expect(lfs_objects.where(file_store: 1).count).to eq(1)
+    expect(uploads.where(store: 1).count).to eq(1)
+  end
+end