diff --git a/Cargo.lock b/Cargo.lock
index e58b25b608..1540551f44 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1635,6 +1635,16 @@ dependencies = [
  "vec_map",
 ]
 
+[[package]]
+name = "client-legacy"
+version = "0.1.0"
+dependencies = [
+ "bp-messages",
+ "parity-scale-codec",
+ "scale-info",
+ "sp-runtime",
+]
+
 [[package]]
 name = "colorchoice"
 version = "1.0.0"
diff --git a/Cargo.toml b/Cargo.toml
index 8a071c38a7..409824aaed 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -12,6 +12,7 @@ members = [
 	"relay-clients/client-bridge-hub-rococo",
 	"relay-clients/client-bridge-hub-westend",
 	"relay-clients/client-kusama",
+	"relay-clients/client-legacy",
 	"relay-clients/client-polkadot",
 	"relay-clients/client-polkadot-bulletin",
 	"relay-clients/client-rococo",
diff --git a/relay-clients/client-legacy/Cargo.toml b/relay-clients/client-legacy/Cargo.toml
new file mode 100644
index 0000000000..9f25248232
--- /dev/null
+++ b/relay-clients/client-legacy/Cargo.toml
@@ -0,0 +1,20 @@
+[package]
+name = "relay-legacy-client"
+version = "0.1.0"
+authors.workspace = true
+edition.workspace = true
+license = "GPL-3.0-or-later WITH Classpath-exception-2.0"
+repository.workspace = true
+
+[lints]
+workspace = true
+
+[dependencies]
+codec = { package = "parity-scale-codec", version = "3.6.1", features = ["derive"] }
+scale-info = { version = "2.11.3", default-features = false, features = ["derive"] }
+
+# Bridge dependencies
+bp-messages = { git = "https://github.com/paritytech/polkadot-sdk", branch = "bko-bridges-v2-compact-proofs" }
+
+# Substrate Dependencies
+sp-runtime = { git = "https://github.com/paritytech/polkadot-sdk", branch = "bko-bridges-v2-compact-proofs" }
diff --git a/relay-clients/client-legacy/src/lib.rs b/relay-clients/client-legacy/src/lib.rs
new file mode 100644
index 0000000000..e5a5f5a262
--- /dev/null
+++ b/relay-clients/client-legacy/src/lib.rs
@@ -0,0 +1,77 @@
+// Copyright 2019-2021 Parity Technologies (UK) Ltd.
+// This file is part of Parity Bridges Common.
+
+// Parity Bridges Common is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity Bridges Common is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity Bridges Common.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Types used to ensure compatibility with older versions of various types from `polkadot-sdk`.
+//!
+//! E.g. When a runtime is changed and uses different or newer types for the same struct, we can add
+//! the older versions here and use them with `tools/runtime-codegen` for `TypeSubstitute`.
+
+/// Types compatible with versions before the "compact proofs" feature.
+pub mod non_compact_proofs {
+	pub mod bridge_runtime_common {
+		pub mod messages {
+			use bp_messages::{LaneId, MessageNonce};
+			use codec::{Decode, Encode};
+			use scale_info::TypeInfo;
+			use sp_runtime::RuntimeDebug;
+
+			/// Raw storage proof type (just raw trie nodes).
+			pub type RawStorageProof = Vec<Vec<u8>>;
+
+			pub mod source {
+				use super::*;
+
+				/// Messages delivery proof from bridged chain:
+				///
+				/// - hash of finalized header;
+				/// - storage proof of inbound lane state;
+				/// - lane id.
+				#[derive(Clone, Decode, Encode, Eq, PartialEq, RuntimeDebug, TypeInfo)]
+				pub struct FromBridgedChainMessagesDeliveryProof<BridgedHeaderHash> {
+					/// Hash of the bridge header the proof is for.
+					pub bridged_header_hash: BridgedHeaderHash,
+					/// Storage trie proof generated for [`Self::bridged_header_hash`].
+					pub storage_proof: RawStorageProof,
+					/// Lane id of which messages were delivered and the proof is for.
+					pub lane: LaneId,
+				}
+			}
+			pub mod target {
+				use super::*;
+
+				/// Messages proof from bridged chain:
+				///
+				/// - hash of finalized header;
+				/// - storage proof of messages and (optionally) outbound lane state;
+				/// - lane id;
+				/// - nonces (inclusive range) of messages which are included in this proof.
+				#[derive(Clone, Decode, Encode, Eq, PartialEq, RuntimeDebug, TypeInfo)]
+				pub struct FromBridgedChainMessagesProof<BridgedHeaderHash> {
+					/// Hash of the finalized bridged header the proof is for.
+					pub bridged_header_hash: BridgedHeaderHash,
+					/// A storage trie proof of messages being delivered.
+					pub storage_proof: RawStorageProof,
+					/// Messages in this proof are sent over this lane.
+					pub lane: LaneId,
+					/// Nonce of the first message being delivered.
+					pub nonces_start: MessageNonce,
+					/// Nonce of the last message being delivered.
+					pub nonces_end: MessageNonce,
+				}
+			}
+		}
+	}
+}
diff --git a/tools/runtime-codegen/src/main.rs b/tools/runtime-codegen/src/main.rs
index 87ce08d79a..04b20c28d1 100644
--- a/tools/runtime-codegen/src/main.rs
+++ b/tools/runtime-codegen/src/main.rs
@@ -140,6 +140,14 @@ fn main() -> color_eyre::Result<()> {
 		TypeSubstitute::simple("bp_header_chain::InitializationData"),
 		TypeSubstitute::simple("bp_polkadot_core::parachains::ParaId"),
 		TypeSubstitute::simple("bp_polkadot_core::parachains::ParaHeadsProof"),
+		TypeSubstitute::custom(
+			"bridge_runtime_common::messages::target::FromBridgedChainMessagesProof",
+			"::relay_legacy_client::non_compact_proofs::bridge_runtime_common::messages::target::FromBridgedChainMessagesProof",
+		),
+		TypeSubstitute::custom(
+			"bridge_runtime_common::messages::source::FromBridgedChainMessagesDeliveryProof",
+			"::relay_legacy_client::non_compact_proofs::bridge_runtime_common::messages::source::FromBridgedChainMessagesDeliveryProof",
+		),
 		TypeSubstitute::simple(
 			"bp_messages::target_chain::FromBridgedChainMessagesProof",
 		),