diff --git a/lib/db/schemas/payment.ex b/lib/db/schemas/payment.ex
index 29bf9d5..9f69bfe 100644
--- a/lib/db/schemas/payment.ex
+++ b/lib/db/schemas/payment.ex
@@ -56,6 +56,6 @@ defmodule Tokenizer.DB.Schemas.Payment do
     |> validate_length(:description, max: 250)
     |> validate_fee(:amount, :fee, fees)
     |> validate_metadata(:metadata)
-    |> unique_constraint(:external_id)
+    |> unique_constraint(:external_id, name: :payments_external_id_index)
   end
 end