diff --git a/db/migrate/20221012135202_add_index_to_custom_values.rb b/db/migrate/20221012135202_add_index_to_custom_values.rb
new file mode 100644
index 000000000..b6580122e
--- /dev/null
+++ b/db/migrate/20221012135202_add_index_to_custom_values.rb
@@ -0,0 +1,8 @@
+class AddIndexToCustomValues < ActiveRecord::Migration[6.1]
+  def change
+    say_with_time 'Adding unique index on custom_values, this may take some time...' do
+      add_index :custom_values, [:customized_type, :customized_id, :custom_field_id], name: :custom_values_customized_custom_field
+      remove_index :custom_values, column: [:customized_type, :customized_id], name: :custom_values_customized
+    end
+  end
+end