diff --git a/crates/erc20_payment_lib_common/migrations/20240320000000_add_idx.sql b/crates/erc20_payment_lib_common/migrations/20240320000000_add_idx.sql
index 6972ff29..67841b8b 100644
--- a/crates/erc20_payment_lib_common/migrations/20240320000000_add_idx.sql
+++ b/crates/erc20_payment_lib_common/migrations/20240320000000_add_idx.sql
@@ -1,4 +1,5 @@
-CREATE INDEX "idx_chain_tx_tx_hash" ON "chain_tx" ("tx_hash");
+DELETE FROM chain_tx;
+CREATE UNIQUE INDEX "idx_chain_tx_tx_hash" ON "chain_tx" ("tx_hash");
 CREATE INDEX "idx_chain_tx_blockchain_date" ON "chain_tx" ("blockchain_date");
 CREATE INDEX "idx_chain_transfer_blockchain_date" ON "chain_transfer" ("blockchain_date");
 CREATE INDEX "idx_chain_transfer_receiver_address" ON "chain_transfer" ("receiver_addr");
diff --git a/crates/erc20_payment_lib_common/migrations/20240320000001_add_idx.sql b/crates/erc20_payment_lib_common/migrations/20240320000001_add_idx.sql
deleted file mode 100644
index 84bb17d9..00000000
--- a/crates/erc20_payment_lib_common/migrations/20240320000001_add_idx.sql
+++ /dev/null
@@ -1,2 +0,0 @@
-DROP INDEX "idx_chain_tx_tx_hash";
-CREATE UNIQUE INDEX "idx_chain_tx_tx_hash" ON "chain_tx" ("tx_hash");