diff --git a/modules/messages/src/inbound_lane.rs b/modules/messages/src/inbound_lane.rs
index 59ff566719586..fa6480d962fb4 100644
--- a/modules/messages/src/inbound_lane.rs
+++ b/modules/messages/src/inbound_lane.rs
@@ -153,7 +153,7 @@ impl<S: InboundLaneStorage> InboundLane<S> {
 		// Note: There will be max. 1 record to update as we don't allow messages from relayers to
 		// overlap.
 		match data.relayers.front_mut() {
-			Some(entry) if entry.messages.begin < new_confirmed_nonce => {
+			Some(entry) if entry.messages.begin <= new_confirmed_nonce => {
 				entry.messages.begin = new_confirmed_nonce + 1;
 			},
 			_ => {},
@@ -221,12 +221,13 @@ mod tests {
 	use crate::{
 		inbound_lane,
 		mock::{
-			dispatch_result, inbound_message_data, run_test, unrewarded_relayer,
-			TestMessageDispatch, TestRuntime, REGULAR_PAYLOAD, TEST_LANE_ID, TEST_RELAYER_A,
-			TEST_RELAYER_B, TEST_RELAYER_C,
+			dispatch_result, inbound_message_data, inbound_unrewarded_relayers_state, run_test,
+			unrewarded_relayer, TestMessageDispatch, TestRuntime, REGULAR_PAYLOAD, TEST_LANE_ID,
+			TEST_RELAYER_A, TEST_RELAYER_B, TEST_RELAYER_C,
 		},
 		RuntimeInboundLaneStorage,
 	};
+	use bp_messages::UnrewardedRelayersState;
 
 	fn receive_regular_message(
 		lane: &mut InboundLane<RuntimeInboundLaneStorage<TestRuntime, ()>>,
@@ -545,4 +546,29 @@ mod tests {
 			);
 		});
 	}
+
+	#[test]
+	fn first_message_is_confirmed_correctly() {
+		run_test(|| {
+			let mut lane = inbound_lane::<TestRuntime, _>(TEST_LANE_ID);
+			receive_regular_message(&mut lane, 1);
+			receive_regular_message(&mut lane, 2);
+			assert_eq!(
+				lane.receive_state_update(OutboundLaneData {
+					latest_received_nonce: 1,
+					..Default::default()
+				}),
+				Some(1),
+			);
+			assert_eq!(
+				inbound_unrewarded_relayers_state(TEST_LANE_ID),
+				UnrewardedRelayersState {
+					unrewarded_relayer_entries: 1,
+					messages_in_oldest_entry: 1,
+					total_messages: 1,
+					last_delivered_nonce: 2,
+				},
+			);
+		});
+	}
 }
diff --git a/modules/messages/src/lib.rs b/modules/messages/src/lib.rs
index c94f5ffa752fa..6985b9018e701 100644
--- a/modules/messages/src/lib.rs
+++ b/modules/messages/src/lib.rs
@@ -949,12 +949,12 @@ fn verify_and_decode_messages_proof<Chain: SourceHeaderChain, DispatchPayload: D
 mod tests {
 	use super::*;
 	use crate::mock::{
-		message, message_payload, run_test, unrewarded_relayer, AccountId, DbWeight,
-		RuntimeEvent as TestEvent, RuntimeOrigin, TestDeliveryConfirmationPayments,
-		TestDeliveryPayments, TestMessagesDeliveryProof, TestMessagesProof, TestRelayer,
-		TestRuntime, TestWeightInfo, MAX_OUTBOUND_PAYLOAD_SIZE, PAYLOAD_REJECTED_BY_TARGET_CHAIN,
-		REGULAR_PAYLOAD, TEST_LANE_ID, TEST_LANE_ID_2, TEST_LANE_ID_3, TEST_RELAYER_A,
-		TEST_RELAYER_B,
+		inbound_unrewarded_relayers_state, message, message_payload, run_test, unrewarded_relayer,
+		AccountId, DbWeight, RuntimeEvent as TestEvent, RuntimeOrigin,
+		TestDeliveryConfirmationPayments, TestDeliveryPayments, TestMessagesDeliveryProof,
+		TestMessagesProof, TestRelayer, TestRuntime, TestWeightInfo, MAX_OUTBOUND_PAYLOAD_SIZE,
+		PAYLOAD_REJECTED_BY_TARGET_CHAIN, REGULAR_PAYLOAD, TEST_LANE_ID, TEST_LANE_ID_2,
+		TEST_LANE_ID_3, TEST_RELAYER_A, TEST_RELAYER_B,
 	};
 	use bp_messages::{BridgeMessagesCall, UnrewardedRelayer, UnrewardedRelayersState};
 	use bp_test_utils::generate_owned_bridge_module_tests;
@@ -973,23 +973,6 @@ mod tests {
 		System::<TestRuntime>::reset_events();
 	}
 
-	fn inbound_unrewarded_relayers_state(
-		lane: bp_messages::LaneId,
-	) -> bp_messages::UnrewardedRelayersState {
-		let inbound_lane_data = InboundLanes::<TestRuntime, ()>::get(lane).0;
-		let last_delivered_nonce = inbound_lane_data.last_delivered_nonce();
-		let relayers = inbound_lane_data.relayers;
-		bp_messages::UnrewardedRelayersState {
-			unrewarded_relayer_entries: relayers.len() as _,
-			messages_in_oldest_entry: relayers
-				.front()
-				.map(|entry| 1 + entry.messages.end - entry.messages.begin)
-				.unwrap_or(0),
-			total_messages: total_unrewarded_messages(&relayers).unwrap_or(MessageNonce::MAX),
-			last_delivered_nonce,
-		}
-	}
-
 	fn send_regular_message() {
 		get_ready_for_events();
 
diff --git a/modules/messages/src/mock.rs b/modules/messages/src/mock.rs
index 75f05b4820a8a..270222a1fd6ed 100644
--- a/modules/messages/src/mock.rs
+++ b/modules/messages/src/mock.rs
@@ -26,8 +26,8 @@ use bp_messages::{
 		DeliveryPayments, DispatchMessage, DispatchMessageData, MessageDispatch,
 		ProvedLaneMessages, ProvedMessages, SourceHeaderChain,
 	},
-	DeliveredMessages, InboundLaneData, LaneId, Message, MessageKey, MessageNonce, MessagePayload,
-	OutboundLaneData, UnrewardedRelayer,
+	total_unrewarded_messages, DeliveredMessages, InboundLaneData, LaneId, Message, MessageKey,
+	MessageNonce, MessagePayload, OutboundLaneData, UnrewardedRelayer, UnrewardedRelayersState,
 };
 use bp_runtime::{messages::MessageDispatchResult, Size};
 use codec::{Decode, Encode};
@@ -142,7 +142,7 @@ impl pallet_balances::Config for TestRuntime {
 parameter_types! {
 	pub const MaxMessagesToPruneAtOnce: u64 = 10;
 	pub const MaxUnrewardedRelayerEntriesAtInboundLane: u64 = 16;
-	pub const MaxUnconfirmedMessagesAtInboundLane: u64 = 32;
+	pub const MaxUnconfirmedMessagesAtInboundLane: u64 = 128;
 	pub const TestBridgedChainId: bp_runtime::ChainId = *b"test";
 	pub const ActiveOutboundLanes: &'static [LaneId] = &[TEST_LANE_ID, TEST_LANE_ID_2];
 }
@@ -483,6 +483,22 @@ pub fn unrewarded_relayer(
 	UnrewardedRelayer { relayer, messages: DeliveredMessages { begin, end } }
 }
 
+/// Returns unrewarded relayers state at given lane.
+pub fn inbound_unrewarded_relayers_state(lane: bp_messages::LaneId) -> UnrewardedRelayersState {
+	let inbound_lane_data = crate::InboundLanes::<TestRuntime, ()>::get(lane).0;
+	let last_delivered_nonce = inbound_lane_data.last_delivered_nonce();
+	let relayers = inbound_lane_data.relayers;
+	UnrewardedRelayersState {
+		unrewarded_relayer_entries: relayers.len() as _,
+		messages_in_oldest_entry: relayers
+			.front()
+			.map(|entry| 1 + entry.messages.end - entry.messages.begin)
+			.unwrap_or(0),
+		total_messages: total_unrewarded_messages(&relayers).unwrap_or(MessageNonce::MAX),
+		last_delivered_nonce,
+	}
+}
+
 /// Return test externalities to use in tests.
 pub fn new_test_ext() -> sp_io::TestExternalities {
 	let mut t = frame_system::GenesisConfig::default().build_storage::<TestRuntime>().unwrap();