diff --git a/Cargo.lock b/Cargo.lock
index c13c49a45..0e1ae127f 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2316,7 +2316,6 @@ dependencies = [
  "parity-scale-codec",
  "scale-info",
  "sp-core",
- "sp-io",
  "sp-keyring",
  "sp-runtime",
  "sp-std",
diff --git a/pallet/account-migration/Cargo.toml b/pallet/account-migration/Cargo.toml
index db1b78f78..3ad71d51a 100644
--- a/pallet/account-migration/Cargo.toml
+++ b/pallet/account-migration/Cargo.toml
@@ -26,7 +26,6 @@ pallet-assets   = { default-features = false, git = "https://github.com/parityte
 pallet-balances = { default-features = false, git = "https://github.com/paritytech/substrate", branch = "polkadot-v0.9.30" }
 pallet-vesting  = { default-features = false, git = "https://github.com/paritytech/substrate", branch = "polkadot-v0.9.30" }
 sp-core         = { default-features = false, git = "https://github.com/paritytech/substrate", branch = "polkadot-v0.9.30" }
-sp-io           = { default-features = false, git = "https://github.com/paritytech/substrate", branch = "polkadot-v0.9.30" }
 sp-runtime      = { default-features = false, git = "https://github.com/paritytech/substrate", branch = "polkadot-v0.9.30" }
 sp-std          = { default-features = false, git = "https://github.com/paritytech/substrate", branch = "polkadot-v0.9.30" }
 
@@ -52,7 +51,6 @@ std = [
 	"pallet-balances/std",
 	"pallet-vesting/std",
 	"sp-core/std",
-	"sp-io/std",
 	"sp-runtime/std",
 	"sp-std/std",
 ]
diff --git a/pallet/account-migration/src/lib.rs b/pallet/account-migration/src/lib.rs
index b44464923..dccfd7988 100644
--- a/pallet/account-migration/src/lib.rs
+++ b/pallet/account-migration/src/lib.rs
@@ -61,20 +61,18 @@ use frame_system::{pallet_prelude::*, AccountInfo, RawOrigin};
 use pallet_balances::AccountData;
 use pallet_vesting::VestingInfo;
 use sp_core::sr25519::{Public, Signature};
-use sp_io::hashing;
 use sp_runtime::{
 	traits::{IdentityLookup, Verify},
 	AccountId32,
 };
 use sp_std::prelude::*;
 
-type Message = [u8; 32];
-const KTON_ID: u64 = 1026;
-
 #[frame_support::pallet]
 pub mod pallet {
 	use super::*;
 
+	const KTON_ID: u64 = 1026;
+
 	#[pallet::pallet]
 	pub struct Pallet<T>(PhantomData<T>);
 
@@ -94,9 +92,6 @@ pub mod pallet {
 	{
 		/// Override the [`frame_system::Config::RuntimeEvent`].
 		type RuntimeEvent: From<Event> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
-		/// Chain's ID, which is used for constructing the message. (follow EIP-712 SPEC)
-		#[pallet::constant]
-		type ChainId: Get<u64>;
 	}
 
 	#[allow(missing_docs)]
@@ -263,11 +258,7 @@ pub mod pallet {
 				return InvalidTransaction::Custom(E_ACCOUNT_ALREADY_EXISTED).into();
 			}
 
-			let message = sr25519_signable_message(
-				T::ChainId::get(),
-				T::Version::get().spec_name.as_ref(),
-				to,
-			);
+			let message = sr25519_signable_message(T::Version::get().spec_name.as_ref(), to);
 
 			if verify_sr25519_signature(from, &message, signature) {
 				ValidTransaction::with_tag_prefix("account-migration")
@@ -284,25 +275,22 @@ pub mod pallet {
 }
 pub use pallet::*;
 
-fn sr25519_signable_message(
-	chain_id: u64,
-	spec_name: &[u8],
-	account_id_20: &AccountId20,
-) -> Message {
-	hashing::blake2_256(
-		&[
-			&hashing::blake2_256(
-				&[&chain_id.to_le_bytes(), spec_name, b"::account-migration"].concat(),
-			),
-			account_id_20.0.as_slice(),
-		]
-		.concat(),
-	)
+fn sr25519_signable_message(spec_name: &[u8], account_id_20: &AccountId20) -> Vec<u8> {
+	[
+		b"I authorize the migration to ",
+		account_id_20.0.as_slice(),
+		b", an unused address on ",
+		spec_name,
+		b". Sign this message to authorize using the Substrate key associated with the account on ",
+		&spec_name[..spec_name.len() - 1],
+		b" that you wish to migrate.",
+	]
+	.concat()
 }
 
 fn verify_sr25519_signature(
 	public_key: &AccountId32,
-	message: &Message,
+	message: &[u8],
 	signature: &Signature,
 ) -> bool {
 	// Actually, `&[u8]` is `[u8; 32]` here.
@@ -313,5 +301,5 @@ fn verify_sr25519_signature(
 		return false;
 	};
 
-	signature.verify(message.as_slice(), public_key)
+	signature.verify(message, public_key)
 }
diff --git a/pallet/account-migration/src/tests.rs b/pallet/account-migration/src/tests.rs
index be89f89e3..849820ca8 100644
--- a/pallet/account-migration/src/tests.rs
+++ b/pallet/account-migration/src/tests.rs
@@ -23,35 +23,24 @@ use sp_keyring::sr25519::Keyring;
 
 #[test]
 fn sr25519_signable_message_should_work() {
-	[(46_u64, b"Darwinia2".as_slice()), (44, b"Crab2"), (43, b"Pangolin2")]
-		.iter()
-		.zip([
-			[
-				75, 134, 66, 181, 153, 10, 7, 244, 225, 154, 100, 68, 239, 19, 129, 51, 181, 78,
-				66, 254, 167, 54, 211, 20, 171, 68, 160, 46, 216, 98, 9, 44,
-			],
-			[
-				171, 8, 180, 157, 214, 41, 236, 80, 127, 218, 216, 136, 239, 56, 153, 31, 128, 168,
-				154, 112, 70, 245, 19, 68, 53, 29, 49, 95, 238, 209, 238, 129,
-			],
-			[
-				251, 70, 107, 65, 22, 164, 1, 85, 114, 150, 161, 208, 235, 131, 15, 111, 154, 207,
-				193, 216, 110, 54, 58, 177, 15, 99, 104, 179, 13, 30, 55, 205,
-			],
-		])
-		.for_each(|((chain_id, spec_name), message)| {
-			assert_eq!(
-				sr25519_signable_message(*chain_id, spec_name, &Default::default()),
-				message
-			);
-		});
+	["Darwinia2", "Crab2", "Pangolin2"].iter().for_each(|s| {
+		assert_eq!(
+			sr25519_signable_message(s.as_bytes(), &Default::default()),
+			format!(
+				"I authorize the migration to {}, an unused address on {}. Sign this message to authorize using the Substrate key associated with the account on {} that you wish to migrate.",
+				"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00",
+				s,
+				&s[..s.len() - 1],
+			).as_bytes()
+		);
+	});
 }
 
 #[test]
 fn verify_sr25519_signature_should_work() {
 	Keyring::iter().enumerate().for_each(|(i, from)| {
 		let to = [i as _; 20];
-		let message = sr25519_signable_message(46, b"Darwinia2", &to.into());
+		let message = sr25519_signable_message(b"Darwinia2", &to.into());
 		let signature = from.sign(&message);
 
 		assert!(verify_sr25519_signature(&from.public().0.into(), &message, &signature));
diff --git a/runtime/crab/src/pallets/account_migration.rs b/runtime/crab/src/pallets/account_migration.rs
index 1797da2ec..5e230b464 100644
--- a/runtime/crab/src/pallets/account_migration.rs
+++ b/runtime/crab/src/pallets/account_migration.rs
@@ -20,6 +20,5 @@
 use crate::*;
 
 impl darwinia_account_migration::Config for Runtime {
-	type ChainId = <Runtime as pallet_evm::Config>::ChainId;
 	type RuntimeEvent = RuntimeEvent;
 }
diff --git a/runtime/darwinia/src/pallets/account_migration.rs b/runtime/darwinia/src/pallets/account_migration.rs
index 1797da2ec..5e230b464 100644
--- a/runtime/darwinia/src/pallets/account_migration.rs
+++ b/runtime/darwinia/src/pallets/account_migration.rs
@@ -20,6 +20,5 @@
 use crate::*;
 
 impl darwinia_account_migration::Config for Runtime {
-	type ChainId = <Runtime as pallet_evm::Config>::ChainId;
 	type RuntimeEvent = RuntimeEvent;
 }
diff --git a/runtime/pangolin/src/pallets/account_migration.rs b/runtime/pangolin/src/pallets/account_migration.rs
index 6eeca3e9c..5e230b464 100644
--- a/runtime/pangolin/src/pallets/account_migration.rs
+++ b/runtime/pangolin/src/pallets/account_migration.rs
@@ -20,6 +20,5 @@
 use crate::*;
 
 impl darwinia_account_migration::Config for Runtime {
-	type ChainId = <Self as pallet_evm::Config>::ChainId;
 	type RuntimeEvent = RuntimeEvent;
 }