diff --git a/db/migrate/20200126175158_change_last_modified.rb b/db/migrate/20200126175158_change_last_modified.rb
new file mode 100644
index 0000000..93d05de
--- /dev/null
+++ b/db/migrate/20200126175158_change_last_modified.rb
@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+class ChangeLastModified < ActiveRecord::Migration[6.0]
+  def change
+    change_column :access_logs, :sent_http_last_modified, :string
+  end
+end