diff --git a/polkadot/runtime/parachains/src/dmp.rs b/polkadot/runtime/parachains/src/dmp.rs
index 103aeb1e0d..4daa99ffb3 100644
--- a/polkadot/runtime/parachains/src/dmp.rs
+++ b/polkadot/runtime/parachains/src/dmp.rs
@@ -226,6 +226,7 @@ impl<T: Config> Module<T> {
 #[cfg(test)]
 mod tests {
 	use super::*;
+	use hex_literal::hex;
 	use primitives::v1::BlockNumber;
 	use frame_support::StorageValue;
 	use frame_support::traits::{OnFinalize, OnInitialize};
@@ -322,6 +323,25 @@ mod tests {
 		});
 	}
 
+	#[test]
+	fn dmp_mqc_head_fixture() {
+		let a = ParaId::from(2000);
+
+		new_test_ext(default_genesis_config()).execute_with(|| {
+			run_to_block(2, None);
+			assert!(Dmp::dmq_mqc_head(a).is_zero());
+			queue_downward_message(a, vec![1, 2, 3]).unwrap();
+
+			run_to_block(3, None);
+			queue_downward_message(a, vec![4, 5, 6]).unwrap();
+
+			assert_eq!(
+				Dmp::dmq_mqc_head(a),
+				hex!["88dc00db8cc9d22aa62b87807705831f164387dfa49f80a8600ed1cbe1704b6b"].into(),
+			);
+		});
+	}
+
 	#[test]
 	fn check_processed_downward_messages() {
 		let a = ParaId::from(1312);
diff --git a/polkadot/runtime/parachains/src/hrmp.rs b/polkadot/runtime/parachains/src/hrmp.rs
index b3682345cf..55001e2801 100644
--- a/polkadot/runtime/parachains/src/hrmp.rs
+++ b/polkadot/runtime/parachains/src/hrmp.rs
@@ -1536,6 +1536,43 @@ mod tests {
 		});
 	}
 
+	#[test]
+	fn hrmp_mqc_head_fixture() {
+		let para_a = 2000.into();
+		let para_b = 2024.into();
+
+		let mut genesis = GenesisConfigBuilder::default();
+		genesis.hrmp_channel_max_message_size = 20;
+		genesis.hrmp_channel_max_total_size = 20;
+		new_test_ext(genesis.build()).execute_with(|| {
+			register_parachain(para_a);
+			register_parachain(para_b);
+
+			run_to_block(1, Some(vec![1]));
+			Hrmp::init_open_channel(para_a, para_b, 2, 20).unwrap();
+			Hrmp::accept_open_channel(para_b, para_a).unwrap();
+
+			run_to_block(2, Some(vec![2]));
+			let _ = Hrmp::queue_outbound_hrmp(para_a, vec![OutboundHrmpMessage {
+				recipient: para_b,
+				data: vec![1, 2, 3],
+			}]);
+
+			run_to_block(3, None);
+			let _ = Hrmp::queue_outbound_hrmp(para_a, vec![OutboundHrmpMessage {
+				recipient: para_b,
+				data: vec![4, 5, 6],
+			}]);
+
+			assert_eq!(
+				Hrmp::hrmp_mqc_heads(para_b),
+				vec![
+					(para_a, hex_literal::hex!["88dc00db8cc9d22aa62b87807705831f164387dfa49f80a8600ed1cbe1704b6b"].into()),
+				],
+			);
+		});
+	}
+
 	#[test]
 	fn accept_incoming_request_and_offboard() {
 		let para_a = 32.into();