diff --git a/substrate/client/finality-grandpa/src/communication/gossip.rs b/substrate/client/finality-grandpa/src/communication/gossip.rs
index 9795121882..af08e76157 100644
--- a/substrate/client/finality-grandpa/src/communication/gossip.rs
+++ b/substrate/client/finality-grandpa/src/communication/gossip.rs
@@ -84,7 +84,7 @@
 
 use sp_runtime::traits::{NumberFor, Block as BlockT, Zero};
 use network::consensus_gossip::{self as network_gossip, MessageIntent, ValidatorContext};
-use network::{config::Roles, PeerId};
+use network::{config::Roles, PeerId, ReputationChange};
 use codec::{Encode, Decode};
 use fg_primitives::AuthorityId;
 
@@ -114,7 +114,7 @@ const ROUND_DURATION: u32 = 4; // measured in gossip durations
 
 const MIN_LUCKY: usize = 5;
 
-type Report = (PeerId, i32);
+type Report = (PeerId, ReputationChange);
 
 /// An outcome of examining a message.
 #[derive(Debug, PartialEq, Clone, Copy)]
@@ -384,14 +384,19 @@ pub(super) enum Misbehavior {
 }
 
 impl Misbehavior {
-	pub(super) fn cost(&self) -> i32 {
+	pub(super) fn cost(&self) -> ReputationChange {
 		use Misbehavior::*;
 
 		match *self {
 			InvalidViewChange => cost::INVALID_VIEW_CHANGE,
-			UndecodablePacket(bytes) => bytes.saturating_mul(cost::PER_UNDECODABLE_BYTE),
-			BadCatchUpMessage { signatures_checked } =>
+			UndecodablePacket(bytes) => ReputationChange::new(
+				bytes.saturating_mul(cost::PER_UNDECODABLE_BYTE),
+				"Grandpa: Bad packet",
+			),
+			BadCatchUpMessage { signatures_checked } => ReputationChange::new(
 				cost::PER_SIGNATURE_CHECKED.saturating_mul(signatures_checked),
+				"Grandpa: Bad cath-up message",
+			),
 			BadCommitMessage { signatures_checked, blocks_loaded, equivocations_caught } => {
 				let cost = cost::PER_SIGNATURE_CHECKED
 					.saturating_mul(signatures_checked)
@@ -399,7 +404,7 @@ impl Misbehavior {
 
 				let benefit = equivocations_caught.saturating_mul(benefit::PER_EQUIVOCATION);
 
-				(benefit as i32).saturating_add(cost as i32)
+				ReputationChange::new((benefit as i32).saturating_add(cost as i32), "Grandpa: Bad commit")
 			},
 			FutureMessage => cost::FUTURE_MESSAGE,
 			OutOfScopeMessage => cost::OUT_OF_SCOPE_MESSAGE,
@@ -551,11 +556,11 @@ impl<N: Ord> Peers<N> {
 #[derive(Debug, PartialEq)]
 pub(super) enum Action<H>  {
 	// repropagate under given topic, to the given peers, applying cost/benefit to originator.
-	Keep(H, i32),
+	Keep(H, ReputationChange),
 	// discard and process.
-	ProcessAndDiscard(H, i32),
+	ProcessAndDiscard(H, ReputationChange),
 	// discard, applying cost/benefit to originator.
-	Discard(i32),
+	Discard(ReputationChange),
 }
 
 /// State of catch up request handling.
@@ -731,7 +736,7 @@ impl<Block: BlockT> Inner<Block> {
 			.unwrap_or(Consider::RejectOutOfScope)
 	}
 
-	fn cost_past_rejection(&self, _who: &PeerId, _round: Round, _set_id: SetId) -> i32 {
+	fn cost_past_rejection(&self, _who: &PeerId, _round: Round, _set_id: SetId) -> ReputationChange {
 		// hardcoded for now.
 		cost::PAST_REJECTION
 	}
@@ -783,7 +788,6 @@ impl<Block: BlockT> Inner<Block> {
 				return Action::Discard(self.cost_past_rejection(who, full.round, full.set_id)),
 			Consider::RejectOutOfScope => return Action::Discard(Misbehavior::OutOfScopeMessage.cost()),
 			Consider::Accept => {},
-
 		}
 
 		if full.message.precommits.len() != full.message.auth_data.len() || full.message.precommits.is_empty() {
@@ -1221,7 +1225,7 @@ impl<Block: BlockT> GossipValidator<Block> {
 		self.inner.write().note_catch_up_message_processed();
 	}
 
-	fn report(&self, who: PeerId, cost_benefit: i32) {
+	fn report(&self, who: PeerId, cost_benefit: ReputationChange) {
 		let _ = self.report_sender.unbounded_send(PeerReport { who, cost_benefit });
 	}
 
@@ -1443,7 +1447,7 @@ impl<Block: BlockT> network_gossip::Validator<Block> for GossipValidator<Block>
 
 struct PeerReport {
 	who: PeerId,
-	cost_benefit: i32,
+	cost_benefit: ReputationChange,
 }
 
 // wrapper around a stream of reports.
diff --git a/substrate/client/finality-grandpa/src/communication/mod.rs b/substrate/client/finality-grandpa/src/communication/mod.rs
index 8354d41bb0..f705812271 100644
--- a/substrate/client/finality-grandpa/src/communication/mod.rs
+++ b/substrate/client/finality-grandpa/src/communication/mod.rs
@@ -35,7 +35,7 @@ use futures03::stream::{StreamExt, TryStreamExt};
 use grandpa::Message::{Prevote, Precommit, PrimaryPropose};
 use grandpa::{voter, voter_set::VoterSet};
 use log::{debug, trace};
-use network::{consensus_gossip as network_gossip, NetworkService};
+use network::{consensus_gossip as network_gossip, NetworkService, ReputationChange};
 use network_gossip::ConsensusMessage;
 use codec::{Encode, Decode};
 use primitives::Pair;
@@ -65,33 +65,35 @@ pub use fg_primitives::GRANDPA_ENGINE_ID;
 
 // cost scalars for reporting peers.
 mod cost {
-	pub(super) const PAST_REJECTION: i32 = -50;
-	pub(super) const BAD_SIGNATURE: i32 = -100;
-	pub(super) const MALFORMED_CATCH_UP: i32 = -1000;
-	pub(super) const MALFORMED_COMMIT: i32 = -1000;
-	pub(super) const FUTURE_MESSAGE: i32 = -500;
-	pub(super) const UNKNOWN_VOTER: i32 = -150;
+	use network::ReputationChange as Rep;
+	pub(super) const PAST_REJECTION: Rep = Rep::new(-50, "Grandpa: Past message");
+	pub(super) const BAD_SIGNATURE: Rep = Rep::new(-100, "Grandpa: Bad signature");
+	pub(super) const MALFORMED_CATCH_UP: Rep = Rep::new(-1000, "Grandpa: Malformed cath-up");
+	pub(super) const MALFORMED_COMMIT: Rep = Rep::new(-1000, "Grandpa: Malformed commit");
+	pub(super) const FUTURE_MESSAGE: Rep = Rep::new(-500, "Grandpa: Future message");
+	pub(super) const UNKNOWN_VOTER: Rep = Rep::new(-150, "Grandpa: Uknown voter");
 
-	pub(super) const INVALID_VIEW_CHANGE: i32 = -500;
+	pub(super) const INVALID_VIEW_CHANGE: Rep = Rep::new(-500, "Grandpa: Invalid view change");
 	pub(super) const PER_UNDECODABLE_BYTE: i32 = -5;
 	pub(super) const PER_SIGNATURE_CHECKED: i32 = -25;
 	pub(super) const PER_BLOCK_LOADED: i32 = -10;
-	pub(super) const INVALID_CATCH_UP: i32 = -5000;
-	pub(super) const INVALID_COMMIT: i32 = -5000;
-	pub(super) const OUT_OF_SCOPE_MESSAGE: i32 = -500;
-	pub(super) const CATCH_UP_REQUEST_TIMEOUT: i32 = -200;
+	pub(super) const INVALID_CATCH_UP: Rep = Rep::new(-5000, "Grandpa: Invalid catch-up");
+	pub(super) const INVALID_COMMIT: Rep = Rep::new(-5000, "Grandpa: Invalid commit");
+	pub(super) const OUT_OF_SCOPE_MESSAGE: Rep = Rep::new(-500, "Grandpa: Out-of-scope message");
+	pub(super) const CATCH_UP_REQUEST_TIMEOUT: Rep = Rep::new(-200, "Grandpa: Catch-up reqeust timeout");
 
 	// cost of answering a catch up request
-	pub(super) const CATCH_UP_REPLY: i32 = -200;
-	pub(super) const HONEST_OUT_OF_SCOPE_CATCH_UP: i32 = -200;
+	pub(super) const CATCH_UP_REPLY: Rep = Rep::new(-200, "Grandpa: Catch-up reply");
+	pub(super) const HONEST_OUT_OF_SCOPE_CATCH_UP: Rep = Rep::new(-200, "Grandpa: Out-of-scope catch-up");
 }
 
 // benefit scalars for reporting peers.
 mod benefit {
-	pub(super) const NEIGHBOR_MESSAGE: i32 = 100;
-	pub(super) const ROUND_MESSAGE: i32 = 100;
-	pub(super) const BASIC_VALIDATED_CATCH_UP: i32 = 200;
-	pub(super) const BASIC_VALIDATED_COMMIT: i32 = 100;
+	use network::ReputationChange as Rep;
+	pub(super) const NEIGHBOR_MESSAGE: Rep = Rep::new(100, "Grandpa: Neighbor message");
+	pub(super) const ROUND_MESSAGE: Rep = Rep::new(100, "Grandpa: Round message");
+	pub(super) const BASIC_VALIDATED_CATCH_UP: Rep = Rep::new(200, "Grandpa: Catch-up message");
+	pub(super) const BASIC_VALIDATED_COMMIT: Rep = Rep::new(100, "Grandpa: Commit");
 	pub(super) const PER_EQUIVOCATION: i32 = 10;
 }
 
@@ -125,7 +127,7 @@ pub trait Network<Block: BlockT>: Clone + Send + 'static {
 	fn send_message(&self, who: Vec<network::PeerId>, data: Vec<u8>);
 
 	/// Report a peer's cost or benefit after some action.
-	fn report(&self, who: network::PeerId, cost_benefit: i32);
+	fn report(&self, who: network::PeerId, cost_benefit: ReputationChange);
 
 	/// Inform peers that a block with given hash should be downloaded.
 	fn announce(&self, block: Block::Hash, associated_data: Vec<u8>);
@@ -217,7 +219,7 @@ impl<B, S, H> Network<B> for Arc<NetworkService<B, S, H>> where
 		})
 	}
 
-	fn report(&self, who: network::PeerId, cost_benefit: i32) {
+	fn report(&self, who: network::PeerId, cost_benefit: ReputationChange) {
 		self.report_peer(who, cost_benefit)
 	}
 
@@ -803,7 +805,7 @@ fn check_compact_commit<Block: BlockT>(
 	voters: &VoterSet<AuthorityId>,
 	round: Round,
 	set_id: SetId,
-) -> Result<(), i32> {
+) -> Result<(), ReputationChange> {
 	// 4f + 1 = equivocations from f voters.
 	let f = voters.total_weight() - voters.threshold();
 	let full_threshold = voters.total_weight() + f;
@@ -862,7 +864,7 @@ fn check_catch_up<Block: BlockT>(
 	msg: &CatchUp<Block>,
 	voters: &VoterSet<AuthorityId>,
 	set_id: SetId,
-) -> Result<(), i32> {
+) -> Result<(), ReputationChange> {
 	// 4f + 1 = equivocations from f voters.
 	let f = voters.total_weight() - voters.threshold();
 	let full_threshold = voters.total_weight() + f;
@@ -872,7 +874,7 @@ fn check_catch_up<Block: BlockT>(
 		voters: &'a VoterSet<AuthorityId>,
 		votes: impl Iterator<Item=&'a AuthorityId>,
 		full_threshold: u64,
-	) -> Result<(), i32> {
+	) -> Result<(), ReputationChange> {
 		let mut total_weight = 0;
 
 		for id in votes {
@@ -911,7 +913,7 @@ fn check_catch_up<Block: BlockT>(
 		round: RoundNumber,
 		set_id: SetIdNumber,
 		mut signatures_checked: usize,
-	) -> Result<usize, i32> where
+	) -> Result<usize, ReputationChange> where
 		B: BlockT,
 		I: Iterator<Item=(Message<B>, &'a AuthorityId, &'a AuthoritySignature)>,
 	{
diff --git a/substrate/client/finality-grandpa/src/communication/tests.rs b/substrate/client/finality-grandpa/src/communication/tests.rs
index 2d08ecbde7..b36f8ad3e6 100644
--- a/substrate/client/finality-grandpa/src/communication/tests.rs
+++ b/substrate/client/finality-grandpa/src/communication/tests.rs
@@ -37,7 +37,7 @@ enum Event {
 	RegisterValidator(Arc<dyn network_gossip::Validator<Block>>),
 	GossipMessage(Hash, Vec<u8>, bool),
 	SendMessage(Vec<network::PeerId>, Vec<u8>),
-	Report(network::PeerId, i32),
+	Report(network::PeerId, network::ReputationChange),
 	Announce(Hash),
 }
 
@@ -85,7 +85,7 @@ impl super::Network<Block> for TestNetwork {
 	}
 
 	/// Report a peer's cost or benefit after some action.
-	fn report(&self, who: network::PeerId, cost_benefit: i32) {
+	fn report(&self, who: network::PeerId, cost_benefit: network::ReputationChange) {
 		let _ = self.sender.unbounded_send(Event::Report(who, cost_benefit));
 	}
 
diff --git a/substrate/client/network/src/legacy_proto/behaviour.rs b/substrate/client/network/src/legacy_proto/behaviour.rs
index d1d378174a..f890219158 100644
--- a/substrate/client/network/src/legacy_proto/behaviour.rs
+++ b/substrate/client/network/src/legacy_proto/behaviour.rs
@@ -940,7 +940,10 @@ where
 				// a different chain, or a node that doesn't speak the same protocol(s). We
 				// decrease the node's reputation, hence lowering the chances we try this node
 				// again in the short term.
-				self.peerset.report_peer(source.clone(), i32::min_value());
+				self.peerset.report_peer(
+					source.clone(),
+					peerset::ReputationChange::new(i32::min_value(), "Protocol error")
+				);
 				self.disconnect_peer_inner(&source, Some(Duration::from_secs(5)));
 			}
 		}
diff --git a/substrate/client/network/src/lib.rs b/substrate/client/network/src/lib.rs
index 9b25992dd9..1816a21f97 100644
--- a/substrate/client/network/src/lib.rs
+++ b/substrate/client/network/src/lib.rs
@@ -199,6 +199,7 @@ pub use libp2p::multiaddr;
 
 pub use message::{generic as generic_message, RequestId, Status as StatusMessage};
 pub use on_demand_layer::{OnDemand, RemoteResponse};
+pub use peerset::ReputationChange;
 
 // Used by the `construct_simple_protocol!` macro.
 #[doc(hidden)]
diff --git a/substrate/client/network/src/protocol.rs b/substrate/client/network/src/protocol.rs
index 6b9c0755c0..c8a4fadbff 100644
--- a/substrate/client/network/src/protocol.rs
+++ b/substrate/client/network/src/protocol.rs
@@ -88,23 +88,38 @@ const MAX_CONSENSUS_MESSAGES: usize = 256;
 /// and disconnect to free connection slot.
 const LIGHT_MAXIMAL_BLOCKS_DIFFERENCE: u64 = 8192;
 
-/// Reputation change when a peer is "clogged", meaning that it's not fast enough to process our
-/// messages.
-const CLOGGED_PEER_REPUTATION_CHANGE: i32 = -(1 << 12);
-/// Reputation change when a peer doesn't respond in time to our messages.
-const TIMEOUT_REPUTATION_CHANGE: i32 = -(1 << 10);
-/// Reputation change when a peer sends us a status message while we already received one.
-const UNEXPECTED_STATUS_REPUTATION_CHANGE: i32 = -(1 << 20);
-/// Reputation change when we are a light client and a peer is behind us.
-const PEER_BEHIND_US_LIGHT_REPUTATION_CHANGE: i32 = -(1 << 8);
-/// Reputation change when a peer sends us an extrinsic that we didn't know about.
-const GOOD_EXTRINSIC_REPUTATION_CHANGE: i32 = 1 << 7;
-/// Reputation change when a peer sends us a bad extrinsic.
-const BAD_EXTRINSIC_REPUTATION_CHANGE: i32 = -(1 << 12);
-/// We sent an RPC query to the given node, but it failed.
-const RPC_FAILED_REPUTATION_CHANGE: i32 = -(1 << 12);
-/// We received a message that failed to decode.
-const BAD_MESSAGE_REPUTATION_CHANGE: i32 = -(1 << 12);
+mod rep {
+	use peerset::ReputationChange as Rep;
+	/// Reputation change when a peer is "clogged", meaning that it's not fast enough to process our
+	/// messages.
+	pub const CLOGGED_PEER: Rep = Rep::new(-(1 << 12), "Clogged message queue");
+	/// Reputation change when a peer doesn't respond in time to our messages.
+	pub const TIMEOUT: Rep = Rep::new(-(1 << 10), "Request timeout");
+	/// Reputation change when a peer sends us a status message while we already received one.
+	pub const UNEXPECTED_STATUS: Rep = Rep::new(-(1 << 20), "Unexpected status message");
+	/// Reputation change when we are a light client and a peer is behind us.
+	pub const PEER_BEHIND_US_LIGHT: Rep = Rep::new(-(1 << 8), "Useless for a light peer");
+	/// Reputation change when a peer sends us an extrinsic that we didn't know about.
+	pub const GOOD_EXTRINSIC: Rep = Rep::new(1 << 7, "Good extrinsic");
+	/// Reputation change when a peer sends us a bad extrinsic.
+	pub const BAD_EXTRINSIC: Rep = Rep::new(-(1 << 12), "Bad extrinsic");
+	/// We sent an RPC query to the given node, but it failed.
+	pub const RPC_FAILED: Rep = Rep::new(-(1 << 12), "Remote call failed");
+	/// We received a message that failed to decode.
+	pub const BAD_MESSAGE: Rep = Rep::new(-(1 << 12), "Bad message");
+	/// We received an unexpected response.
+	pub const UNEXPECTED_RESPONSE: Rep = Rep::new_fatal("Unexpected response packet");
+	/// We received an unexpected extrinsic packet.
+	pub const UNEXPECTED_EXTRINSICS: Rep = Rep::new_fatal("Unexpected extrinsics packet");
+	/// We received an unexpected light node request.
+	pub const UNEXPECTED_REQUEST: Rep = Rep::new_fatal("Unexpected block request packet");
+	/// Peer has different genesis.
+	pub const GENESIS_MISMATCH: Rep = Rep::new_fatal("Genesis mismatch");
+	/// Peer is on unsupported protocol version.
+	pub const BAD_PROTOCOL: Rep = Rep::new_fatal("Unsupported protocol");
+	/// Peer role does not match (e.g. light peer connecting to another light peer).
+	pub const BAD_ROLE: Rep = Rep::new_fatal("Unsupported role");
+}
 
 // Lock must always be taken in order declared here.
 pub struct Protocol<B: BlockT, S: NetworkSpecialization<B>, H: ExHashT> {
@@ -183,7 +198,7 @@ struct LightDispatchIn<'a> {
 }
 
 impl<'a, B: BlockT> LightDispatchNetwork<B> for LightDispatchIn<'a> {
-	fn report_peer(&mut self, who: &PeerId, reputation: i32) {
+	fn report_peer(&mut self, who: &PeerId, reputation: peerset::ReputationChange) {
 		self.peerset.report_peer(who.clone(), reputation)
 	}
 
@@ -303,7 +318,7 @@ impl<'a, B: BlockT> LightDispatchNetwork<B> for LightDispatchIn<'a> {
 pub trait Context<B: BlockT> {
 	/// Adjusts the reputation of the peer. Use this to point out that a peer has been malign or
 	/// irresponsible or appeared lazy.
-	fn report_peer(&mut self, who: PeerId, reputation: i32);
+	fn report_peer(&mut self, who: PeerId, reputation: peerset::ReputationChange);
 
 	/// Force disconnecting from a peer. Use this when a peer misbehaved.
 	fn disconnect_peer(&mut self, who: PeerId);
@@ -333,7 +348,7 @@ impl<'a, B: BlockT + 'a, H: 'a + ExHashT> ProtocolContext<'a, B, H> {
 }
 
 impl<'a, B: BlockT + 'a, H: ExHashT + 'a> Context<B> for ProtocolContext<'a, B, H> {
-	fn report_peer(&mut self, who: PeerId, reputation: i32) {
+	fn report_peer(&mut self, who: PeerId, reputation: peerset::ReputationChange) {
 		self.peerset_handle.report_peer(who, reputation)
 	}
 
@@ -557,7 +572,7 @@ impl<B: BlockT, S: NetworkSpecialization<B>, H: ExHashT> Protocol<B, S, H> {
 				return request.map(|(_, r)| r)
 			}
 			trace!(target: "sync", "Unexpected response packet from {} ({})", who, response.id);
-			self.peerset_handle.report_peer(who.clone(), i32::min_value());
+			self.peerset_handle.report_peer(who.clone(), rep::UNEXPECTED_RESPONSE);
 			self.behaviour.disconnect_peer(&who);
 		}
 		None
@@ -587,7 +602,7 @@ impl<B: BlockT, S: NetworkSpecialization<B>, H: ExHashT> Protocol<B, S, H> {
 			Ok(message) => message,
 			Err(err) => {
 				debug!(target: "sync", "Couldn't decode packet sent by {}: {:?}: {}", who, data, err.what());
-				self.peerset_handle.report_peer(who.clone(), BAD_MESSAGE_REPUTATION_CHANGE);
+				self.peerset_handle.report_peer(who.clone(), rep::BAD_MESSAGE);
 				return CustomMessageOutcome::None;
 			}
 		};
@@ -755,7 +770,7 @@ impl<B: BlockT, S: NetworkSpecialization<B>, H: ExHashT> Protocol<B, S, H> {
 	/// Called as a back-pressure mechanism if the networking detects that the peer cannot process
 	/// our messaging rate fast enough.
 	pub fn on_clogged_peer(&self, who: PeerId, _msg: Option<Message<B>>) {
-		self.peerset_handle.report_peer(who.clone(), CLOGGED_PEER_REPUTATION_CHANGE);
+		self.peerset_handle.report_peer(who.clone(), rep::CLOGGED_PEER);
 
 		// Print some diagnostics.
 		if let Some(peer) = self.context_data.peers.get(&who) {
@@ -784,7 +799,7 @@ impl<B: BlockT, S: NetworkSpecialization<B>, H: ExHashT> Protocol<B, S, H> {
 		if !self.config.roles.is_full() {
 			trace!(target: "sync", "Peer {} is trying to sync from the light node", peer);
 			self.behaviour.disconnect_peer(&peer);
-			self.peerset_handle.report_peer(peer, i32::min_value());
+			self.peerset_handle.report_peer(peer, rep::UNEXPECTED_REQUEST);
 			return;
 		}
 
@@ -846,7 +861,7 @@ impl<B: BlockT, S: NetworkSpecialization<B>, H: ExHashT> Protocol<B, S, H> {
 	}
 
 	/// Adjusts the reputation of a node.
-	pub fn report_peer(&self, who: PeerId, reputation: i32) {
+	pub fn report_peer(&self, who: PeerId, reputation: peerset::ReputationChange) {
 		self.peerset_handle.report_peer(who, reputation)
 	}
 
@@ -953,7 +968,7 @@ impl<B: BlockT, S: NetworkSpecialization<B>, H: ExHashT> Protocol<B, S, H> {
 		);
 		for p in aborting {
 			self.behaviour.disconnect_peer(&p);
-			self.peerset_handle.report_peer(p, TIMEOUT_REPUTATION_CHANGE);
+			self.peerset_handle.report_peer(p, rep::TIMEOUT);
 		}
 	}
 
@@ -967,7 +982,7 @@ impl<B: BlockT, S: NetworkSpecialization<B>, H: ExHashT> Protocol<B, S, H> {
 					if self.important_peers.contains(&who) { Level::Warn } else { Level::Debug },
 					"Unexpected status packet from {}", who
 				);
-				self.peerset_handle.report_peer(who, UNEXPECTED_STATUS_REPUTATION_CHANGE);
+				self.peerset_handle.report_peer(who, rep::UNEXPECTED_STATUS);
 				return;
 			}
 			if status.genesis_hash != self.genesis_hash {
@@ -977,7 +992,7 @@ impl<B: BlockT, S: NetworkSpecialization<B>, H: ExHashT> Protocol<B, S, H> {
 					"Peer is on different chain (our genesis: {} theirs: {})",
 					self.genesis_hash, status.genesis_hash
 				);
-				self.peerset_handle.report_peer(who.clone(), i32::min_value());
+				self.peerset_handle.report_peer(who.clone(), rep::GENESIS_MISMATCH);
 				self.behaviour.disconnect_peer(&who);
 				return;
 			}
@@ -987,7 +1002,7 @@ impl<B: BlockT, S: NetworkSpecialization<B>, H: ExHashT> Protocol<B, S, H> {
 					if self.important_peers.contains(&who) { Level::Warn } else { Level::Trace },
 					"Peer {:?} using unsupported protocol version {}", who, status.version
 				);
-				self.peerset_handle.report_peer(who.clone(), i32::min_value());
+				self.peerset_handle.report_peer(who.clone(), rep::BAD_PROTOCOL);
 				self.behaviour.disconnect_peer(&who);
 				return;
 			}
@@ -996,7 +1011,7 @@ impl<B: BlockT, S: NetworkSpecialization<B>, H: ExHashT> Protocol<B, S, H> {
 				// we're not interested in light peers
 				if status.roles.is_light() {
 					debug!(target: "sync", "Peer {} is unable to serve light requests", who);
-					self.peerset_handle.report_peer(who.clone(), i32::min_value());
+					self.peerset_handle.report_peer(who.clone(), rep::BAD_ROLE);
 					self.behaviour.disconnect_peer(&who);
 					return;
 				}
@@ -1013,7 +1028,7 @@ impl<B: BlockT, S: NetworkSpecialization<B>, H: ExHashT> Protocol<B, S, H> {
 					.saturated_into::<u64>();
 				if blocks_difference > LIGHT_MAXIMAL_BLOCKS_DIFFERENCE {
 					debug!(target: "sync", "Peer {} is far behind us and will unable to serve light requests", who);
-					self.peerset_handle.report_peer(who.clone(), PEER_BEHIND_US_LIGHT_REPUTATION_CHANGE);
+					self.peerset_handle.report_peer(who.clone(), rep::PEER_BEHIND_US_LIGHT);
 					self.behaviour.disconnect_peer(&who);
 					return;
 				}
@@ -1082,7 +1097,7 @@ impl<B: BlockT, S: NetworkSpecialization<B>, H: ExHashT> Protocol<B, S, H> {
 		if !self.config.roles.is_full() {
 			trace!(target: "sync", "Peer {} is trying to send extrinsic to the light node", who);
 			self.behaviour.disconnect_peer(&who);
-			self.peerset_handle.report_peer(who, i32::min_value());
+			self.peerset_handle.report_peer(who, rep::UNEXPECTED_EXTRINSICS);
 			return;
 		}
 
@@ -1100,8 +1115,8 @@ impl<B: BlockT, S: NetworkSpecialization<B>, H: ExHashT> Protocol<B, S, H> {
 				self.transaction_pool.import(
 					self.peerset_handle.clone().into(),
 					who.clone(),
-					GOOD_EXTRINSIC_REPUTATION_CHANGE,
-					BAD_EXTRINSIC_REPUTATION_CHANGE,
+					rep::GOOD_EXTRINSIC,
+					rep::BAD_EXTRINSIC,
 					t,
 				);
 			}
@@ -1351,7 +1366,7 @@ impl<B: BlockT, S: NetworkSpecialization<B>, H: ExHashT> Protocol<B, S, H> {
 					request.block,
 					error
 				);
-				self.peerset_handle.report_peer(who.clone(), RPC_FAILED_REPUTATION_CHANGE);
+				self.peerset_handle.report_peer(who.clone(), rep::RPC_FAILED);
 				StorageProof::empty()
 			}
 		};
@@ -1679,7 +1694,7 @@ impl<B: BlockT, S: NetworkSpecialization<B>, H: ExHashT> Protocol<B, S, H> {
 				None
 			},
 		};
- 		self.send_message(
+		self.send_message(
 			&who,
 			GenericMessage::FinalityProofResponse(message::FinalityProofResponse {
 				id: 0,
diff --git a/substrate/client/network/src/protocol/consensus_gossip.rs b/substrate/client/network/src/protocol/consensus_gossip.rs
index 3062047952..24561debef 100644
--- a/substrate/client/network/src/protocol/consensus_gossip.rs
+++ b/substrate/client/network/src/protocol/consensus_gossip.rs
@@ -61,15 +61,19 @@ use crate::config::Roles;
 const KNOWN_MESSAGES_CACHE_SIZE: usize = 4096;
 
 const REBROADCAST_INTERVAL: time::Duration = time::Duration::from_secs(30);
-/// Reputation change when a peer sends us a gossip message that we didn't know about.
-const GOSSIP_SUCCESS_REPUTATION_CHANGE: i32 = 1 << 4;
-/// Reputation change when a peer sends us a gossip message that we already knew about.
-const DUPLICATE_GOSSIP_REPUTATION_CHANGE: i32 = -(1 << 2);
-/// Reputation change when a peer sends us a gossip message for an unknown engine, whatever that
-/// means.
-const UNKNOWN_GOSSIP_REPUTATION_CHANGE: i32 = -(1 << 6);
-/// Reputation change when a peer sends a message from a topic it isn't registered on.
-const UNREGISTERED_TOPIC_REPUTATION_CHANGE: i32 = -(1 << 10);
+
+mod rep {
+	use peerset::ReputationChange as Rep;
+	/// Reputation change when a peer sends us a gossip message that we didn't know about.
+	pub const GOSSIP_SUCCESS: Rep = Rep::new(1 << 4, "Successfull gossip");
+	/// Reputation change when a peer sends us a gossip message that we already knew about.
+	pub const DUPLICATE_GOSSIP: Rep = Rep::new(-(1 << 2), "Duplicate gossip");
+	/// Reputation change when a peer sends us a gossip message for an unknown engine, whatever that
+	/// means.
+	pub const UNKNOWN_GOSSIP: Rep = Rep::new(-(1 << 6), "Unknown gossup message engine id");
+	/// Reputation change when a peer sends a message from a topic it isn't registered on.
+	pub const UNREGISTERED_TOPIC: Rep = Rep::new(-(1 << 10), "Unregistered gossip message topic");
+}
 
 struct PeerConsensus<H> {
 	known_messages: HashSet<H>,
@@ -470,7 +474,7 @@ impl<B: BlockT> ConsensusGossip<B> {
 
 			if self.known_messages.contains(&message_hash) {
 				trace!(target:"gossip", "Ignored already known message from {}", who);
-				protocol.report_peer(who.clone(), DUPLICATE_GOSSIP_REPUTATION_CHANGE);
+				protocol.report_peer(who.clone(), rep::DUPLICATE_GOSSIP);
 				continue;
 			}
 
@@ -489,14 +493,14 @@ impl<B: BlockT> ConsensusGossip<B> {
 				Some(ValidationResult::Discard) => None,
 				None => {
 					trace!(target:"gossip", "Unknown message engine id {:?} from {}", engine_id, who);
-					protocol.report_peer(who.clone(), UNKNOWN_GOSSIP_REPUTATION_CHANGE);
+					protocol.report_peer(who.clone(), rep::UNKNOWN_GOSSIP);
 					protocol.disconnect_peer(who.clone());
 					continue;
 				}
 			};
 
 			if let Some((topic, keep)) = validation_result {
-				protocol.report_peer(who.clone(), GOSSIP_SUCCESS_REPUTATION_CHANGE);
+				protocol.report_peer(who.clone(), rep::GOSSIP_SUCCESS);
 				if let Some(ref mut peer) = self.peers.get_mut(&who) {
 					peer.known_messages.insert(message_hash);
 					if let Entry::Occupied(mut entry) = self.live_message_sinks.entry((engine_id, topic)) {
@@ -519,7 +523,7 @@ impl<B: BlockT> ConsensusGossip<B> {
 					}
 				} else {
 					trace!(target:"gossip", "Ignored statement from unregistered peer {}", who);
-					protocol.report_peer(who.clone(), UNREGISTERED_TOPIC_REPUTATION_CHANGE);
+					protocol.report_peer(who.clone(), rep::UNREGISTERED_TOPIC);
 				}
 			} else {
 				trace!(target:"gossip", "Handled valid one hop message from peer {}", who);
diff --git a/substrate/client/network/src/protocol/light_dispatch.rs b/substrate/client/network/src/protocol/light_dispatch.rs
index 7d37b49b6c..ef240cbf06 100644
--- a/substrate/client/network/src/protocol/light_dispatch.rs
+++ b/substrate/client/network/src/protocol/light_dispatch.rs
@@ -33,6 +33,7 @@ use crate::message::{self, BlockAttributes, Direction, FromBlock, RequestId};
 use libp2p::PeerId;
 use crate::config::Roles;
 use sp_runtime::traits::{Block as BlockT, Header as HeaderT, NumberFor};
+use peerset::ReputationChange;
 
 /// Remote request timeout.
 const REQUEST_TIMEOUT: Duration = Duration::from_secs(15);
@@ -44,7 +45,7 @@ const TIMEOUT_REPUTATION_CHANGE: i32 = -(1 << 8);
 /// Trait used by the `LightDispatch` service to communicate messages back to the network.
 pub trait LightDispatchNetwork<B: BlockT> {
 	/// Adjusts the reputation of the given peer.
-	fn report_peer(&mut self, who: &PeerId, reputation_change: i32);
+	fn report_peer(&mut self, who: &PeerId, reputation_change: ReputationChange);
 
 	/// Disconnect from the given peer. Used in case of misbehaviour.
 	fn disconnect_peer(&mut self, who: &PeerId);
@@ -267,7 +268,7 @@ impl<B: BlockT> LightDispatch<B> where
 			Some(request) => request,
 			None => {
 				info!("Invalid remote {} response from peer {}", rtype, peer);
-				network.report_peer(&peer, i32::min_value());
+				network.report_peer(&peer, ReputationChange::new_fatal("Invalid remote response"));
 				network.disconnect_peer(&peer);
 				self.remove_peer(peer);
 				return;
@@ -279,7 +280,7 @@ impl<B: BlockT> LightDispatch<B> where
 			Accept::Ok => (retry_count, None),
 			Accept::CheckFailed(error, retry_request_data) => {
 				info!("Failed to check remote {} response from peer {}: {}", rtype, peer, error);
-				network.report_peer(&peer, i32::min_value());
+				network.report_peer(&peer, ReputationChange::new_fatal("Failed remote response check"));
 				network.disconnect_peer(&peer);
 				self.remove_peer(peer);
 
@@ -293,7 +294,7 @@ impl<B: BlockT> LightDispatch<B> where
 			},
 			Accept::Unexpected(retry_request_data) => {
 				info!("Unexpected response to remote {} from peer", rtype);
-				network.report_peer(&peer, i32::min_value());
+				network.report_peer(&peer, ReputationChange::new_fatal("Unexpected remote response"));
 				network.disconnect_peer(&peer);
 				self.remove_peer(peer);
 
@@ -350,7 +351,7 @@ impl<B: BlockT> LightDispatch<B> where
 
 			let (bad_peer, request) = self.active_peers.pop_front().expect("front() is Some as checked above");
 			self.pending_requests.push_front(request);
-			network.report_peer(&bad_peer, TIMEOUT_REPUTATION_CHANGE);
+			network.report_peer(&bad_peer, ReputationChange::new(TIMEOUT_REPUTATION_CHANGE, "Light request timeout"));
 			network.disconnect_peer(&bad_peer);
 		}
 
@@ -800,7 +801,7 @@ pub mod tests {
 	}
 
 	impl<'a, B: BlockT> LightDispatchNetwork<B> for &'a mut DummyNetwork {
-		fn report_peer(&mut self, _: &PeerId, _: i32) {}
+		fn report_peer(&mut self, _: &PeerId, _: crate::ReputationChange) {}
 		fn disconnect_peer(&mut self, who: &PeerId) {
 			self.disconnected_peers.insert(who.clone());
 		}
diff --git a/substrate/client/network/src/protocol/sync.rs b/substrate/client/network/src/protocol/sync.rs
index 01f36bd4da..ca332d46f1 100644
--- a/substrate/client/network/src/protocol/sync.rs
+++ b/substrate/client/network/src/protocol/sync.rs
@@ -72,29 +72,34 @@ const MAJOR_SYNC_BLOCKS: u8 = 5;
 /// Number of recently announced blocks to track for each peer.
 const ANNOUNCE_HISTORY_SIZE: usize = 64;
 
-/// Reputation change when a peer sent us a status message that led to a
-/// database read error.
-const BLOCKCHAIN_STATUS_READ_ERROR_REPUTATION_CHANGE: i32 = -(1 << 16);
+mod rep {
+	use peerset::ReputationChange as Rep;
+	/// Reputation change when a peer sent us a message that led to a
+	/// database read error.
+	pub const BLOCKCHAIN_READ_ERROR: Rep = Rep::new(-(1 << 16), "DB Error");
 
-/// Reputation change when a peer failed to answer our legitimate ancestry
-/// block search.
-const ANCESTRY_BLOCK_ERROR_REPUTATION_CHANGE: i32 = -(1 << 9);
+	/// Reputation change when a peer sent us a status message with a different
+	/// genesis than us.
+	pub const GENESIS_MISMATCH: Rep = Rep::new(i32::min_value(), "Genesis mismatch");
 
-/// Reputation change when a peer sent us a status message with a different
-/// genesis than us.
-const GENESIS_MISMATCH_REPUTATION_CHANGE: i32 = i32::min_value() + 1;
+	/// Reputation change for peers which send us a block with an incomplete header.
+	pub const INCOMPLETE_HEADER: Rep = Rep::new(-(1 << 20), "Incomplete header");
 
-/// Reputation change for peers which send us a block with an incomplete header.
-const INCOMPLETE_HEADER_REPUTATION_CHANGE: i32 = -(1 << 20);
+	/// Reputation change for peers which send us a block which we fail to verify.
+	pub const VERIFICATION_FAIL: Rep = Rep::new(-(1 << 20), "Block verification failed");
 
-/// Reputation change for peers which send us a block which we fail to verify.
-const VERIFICATION_FAIL_REPUTATION_CHANGE: i32 = -(1 << 20);
+	/// Reputation change for peers which send us a known bad block.
+	pub const BAD_BLOCK: Rep = Rep::new(-(1 << 29), "Bad block");
 
-/// Reputation change for peers which send us a bad block.
-const BAD_BLOCK_REPUTATION_CHANGE: i32 = -(1 << 29);
+	/// Reputation change for peers which send us a block with bad justifications.
+	pub const BAD_JUSTIFICATION: Rep = Rep::new(-(1 << 16), "Bad justification");
 
-/// Reputation change for peers which send us a block with bad justifications.
-const BAD_JUSTIFICATION_REPUTATION_CHANGE: i32 = -(1 << 16);
+	/// Reputation change for peers which send us a block with bad finality proof.
+	pub const BAD_FINALITY_PROOF: Rep = Rep::new(-(1 << 16), "Bad finality proof");
+
+	/// Reputation change when a peer sent us invlid ancestry result.
+	pub const UNKNOWN_ANCESTOR:Rep = Rep::new(-(1 << 16), "DB Error");
+}
 
 /// The main data structure which contains all the state for a chains
 /// active syncing strategy.
@@ -225,11 +230,11 @@ pub struct Status<B: BlockT> {
 
 /// A peer did not behave as expected and should be reported.
 #[derive(Debug, Clone, PartialEq, Eq)]
-pub struct BadPeer(pub PeerId, pub i32);
+pub struct BadPeer(pub PeerId, pub peerset::ReputationChange);
 
 impl fmt::Display for BadPeer {
 	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-		write!(f, "bad peer {}; reputation change: {}", self.0, self.1)
+		write!(f, "Bad peer {}; Reputation change: {:?}", self.0, self.1)
 	}
 }
 
@@ -358,16 +363,16 @@ impl<B: BlockT> ChainSync<B> {
 		match self.block_status(&best_hash) {
 			Err(e) => {
 				debug!(target:"sync", "Error reading blockchain: {:?}", e);
-				Err(BadPeer(who, BLOCKCHAIN_STATUS_READ_ERROR_REPUTATION_CHANGE))
+				Err(BadPeer(who, rep::BLOCKCHAIN_READ_ERROR))
 			}
 			Ok(BlockStatus::KnownBad) => {
 				info!("New peer with known bad best block {} ({}).", best_hash, best_number);
-				Err(BadPeer(who, i32::min_value()))
+				Err(BadPeer(who, rep::BAD_BLOCK))
 			}
 			Ok(BlockStatus::Unknown) => {
 				if best_number.is_zero() {
 					info!("New peer with unknown genesis hash {} ({}).", best_hash, best_number);
-					return Err(BadPeer(who, i32::min_value()))
+					return Err(BadPeer(who, rep::GENESIS_MISMATCH));
 				}
 				// If there are more than `MAJOR_SYNC_BLOCKS` in the import queue then we have
 				// enough to do in the import queue that it's not worth kicking off
@@ -688,11 +693,11 @@ impl<B: BlockT> ChainSync<B> {
 							},
 							(None, _) => {
 								debug!(target: "sync", "Invalid response when searching for ancestor from {}", who);
-								return Err(BadPeer(who, i32::min_value()))
+								return Err(BadPeer(who, rep::UNKNOWN_ANCESTOR))
 							},
 							(_, Err(e)) => {
 								info!("Error answering legitimate blockchain query: {:?}", e);
-								return Err(BadPeer(who, ANCESTRY_BLOCK_ERROR_REPUTATION_CHANGE))
+								return Err(BadPeer(who, rep::BLOCKCHAIN_READ_ERROR))
 							}
 						};
 						if matching_hash.is_some() && peer.common_number < *num {
@@ -700,7 +705,7 @@ impl<B: BlockT> ChainSync<B> {
 						}
 						if matching_hash.is_none() && num.is_zero() {
 							trace!(target:"sync", "Ancestry search: genesis mismatch for peer {}", who);
-							return Err(BadPeer(who, GENESIS_MISMATCH_REPUTATION_CHANGE))
+							return Err(BadPeer(who, rep::GENESIS_MISMATCH))
 						}
 						if let Some((next_state, next_num)) = handle_ancestor_search_state(state, *num, matching_hash.is_some()) {
 							peer.state = PeerSyncState::AncestorSearch(next_num, next_state);
@@ -790,9 +795,10 @@ impl<B: BlockT> ChainSync<B> {
 			if let Some(block) = response.blocks.into_iter().next() {
 				if hash != block.hash {
 					info!(
+						target: "sync",
 						"Invalid block justification provided by {}: requested: {:?} got: {:?}", who, hash, block.hash
 					);
-					return Err(BadPeer(who, i32::min_value()))
+					return Err(BadPeer(who, rep::BAD_JUSTIFICATION));
 				}
 				if let Some((peer, hash, number, j)) = self.extra_justifications.on_response(who, block.justification) {
 					return Ok(OnBlockJustification::Import { peer, hash, number, justification: j })
@@ -825,8 +831,13 @@ impl<B: BlockT> ChainSync<B> {
 
 			// We only request one finality proof at a time.
 			if hash != resp.block {
-				info!("Invalid block finality proof provided: requested: {:?} got: {:?}", hash, resp.block);
-				return Err(BadPeer(who, i32::min_value()))
+				info!(
+					target: "sync",
+					"Invalid block finality proof provided: requested: {:?} got: {:?}",
+					hash,
+					resp.block
+				);
+				return Err(BadPeer(who, rep::BAD_FINALITY_PROOF));
 			}
 
 			if let Some((peer, hash, number, p)) = self.extra_finality_proofs.on_response(who, resp.proof) {
@@ -887,7 +898,7 @@ impl<B: BlockT> ChainSync<B> {
 					if aux.bad_justification {
 						if let Some(peer) = who {
 							info!("Sent block with bad justification to import");
-							output.push(Err(BadPeer(peer, BAD_JUSTIFICATION_REPUTATION_CHANGE)));
+							output.push(Err(BadPeer(peer, rep::BAD_JUSTIFICATION)));
 						}
 					}
 
@@ -903,21 +914,21 @@ impl<B: BlockT> ChainSync<B> {
 				Err(BlockImportError::IncompleteHeader(who)) => {
 					if let Some(peer) = who {
 						info!("Peer sent block with incomplete header to import");
-						output.push(Err(BadPeer(peer, INCOMPLETE_HEADER_REPUTATION_CHANGE)));
+						output.push(Err(BadPeer(peer, rep::INCOMPLETE_HEADER)));
 						output.extend(self.restart());
 					}
 				},
 				Err(BlockImportError::VerificationFailed(who, e)) => {
 					if let Some(peer) = who {
 						info!("Verification failed from peer: {}", e);
-						output.push(Err(BadPeer(peer, VERIFICATION_FAIL_REPUTATION_CHANGE)));
+						output.push(Err(BadPeer(peer, rep::VERIFICATION_FAIL)));
 						output.extend(self.restart());
 					}
 				},
 				Err(BlockImportError::BadBlock(who)) => {
 					if let Some(peer) = who {
 						info!("Bad block");
-						output.push(Err(BadPeer(peer, BAD_BLOCK_REPUTATION_CHANGE)));
+						output.push(Err(BadPeer(peer, rep::BAD_BLOCK)));
 						output.extend(self.restart());
 					}
 				},
diff --git a/substrate/client/network/src/service.rs b/substrate/client/network/src/service.rs
index 4a60c3def7..85fd1c3ff5 100644
--- a/substrate/client/network/src/service.rs
+++ b/substrate/client/network/src/service.rs
@@ -42,7 +42,7 @@ use sp_runtime::{traits::{Block as BlockT, NumberFor}, ConsensusEngineId};
 
 use crate::{behaviour::{Behaviour, BehaviourOut}, config::{parse_str_addr, parse_addr}};
 use crate::{NetworkState, NetworkStateNotConnectedPeer, NetworkStatePeer};
-use crate::{transport, config::NonReservedPeerMode};
+use crate::{transport, config::NonReservedPeerMode, ReputationChange};
 use crate::config::{Params, TransportConfig};
 use crate::error::Error;
 use crate::protocol::{self, Protocol, Context, CustomMessageOutcome, PeerInfo};
@@ -71,8 +71,8 @@ pub trait TransactionPool<H: ExHashT, B: BlockT>: Send + Sync {
 		&self,
 		report_handle: ReportHandle,
 		who: PeerId,
-		reputation_change_good: i32,
-		reputation_change_bad: i32,
+		reputation_change_good: ReputationChange,
+		reputation_change_bad: ReputationChange,
 		transaction: B::Extrinsic,
 	);
 	/// Notify the pool about transactions broadcast.
@@ -94,7 +94,7 @@ impl From<PeersetHandle> for ReportHandle {
 impl ReportHandle {
 	/// Report a given peer as either beneficial (+) or costly (-) according to the
 	/// given scalar.
-	pub fn report_peer(&self, who: PeerId, cost_benefit: i32) {
+	pub fn report_peer(&self, who: PeerId, cost_benefit: ReputationChange) {
 		self.inner.report_peer(who, cost_benefit);
 	}
 }
@@ -449,7 +449,7 @@ impl<B: BlockT + 'static, S: NetworkSpecialization<B>, H: ExHashT> NetworkServic
 
 	/// Report a given peer as either beneficial (+) or costly (-) according to the
 	/// given scalar.
-	pub fn report_peer(&self, who: PeerId, cost_benefit: i32) {
+	pub fn report_peer(&self, who: PeerId, cost_benefit: ReputationChange) {
 		self.peerset.report_peer(who, cost_benefit);
 	}
 
@@ -786,7 +786,7 @@ impl<'a, B: BlockT, S: NetworkSpecialization<B>, H: ExHashT> Link<B> for Network
 		if !success {
 			info!("Invalid justification provided by {} for #{}", who, hash);
 			self.protocol.user_protocol_mut().disconnect_peer(&who);
-			self.protocol.user_protocol_mut().report_peer(who, i32::min_value());
+			self.protocol.user_protocol_mut().report_peer(who, ReputationChange::new_fatal("Invalid justification"));
 		}
 	}
 	fn request_justification(&mut self, hash: &B::Hash, number: NumberFor<B>) {
@@ -806,7 +806,7 @@ impl<'a, B: BlockT, S: NetworkSpecialization<B>, H: ExHashT> Link<B> for Network
 		if !success {
 			info!("Invalid finality proof provided by {} for #{}", who, request_block.0);
 			self.protocol.user_protocol_mut().disconnect_peer(&who);
-			self.protocol.user_protocol_mut().report_peer(who, i32::min_value());
+			self.protocol.user_protocol_mut().report_peer(who, ReputationChange::new_fatal("Invalid finality proof"));
 		}
 	}
 }
diff --git a/substrate/client/network/src/test/mod.rs b/substrate/client/network/src/test/mod.rs
index d0cac918e7..f016ef99d8 100644
--- a/substrate/client/network/src/test/mod.rs
+++ b/substrate/client/network/src/test/mod.rs
@@ -401,8 +401,8 @@ impl TransactionPool<Hash, Block> for EmptyTransactionPool {
 		&self,
 		_report_handle: ReportHandle,
 		_who: PeerId,
-		_rep_change_good: i32,
-		_rep_change_bad: i32,
+		_rep_change_good: crate::ReputationChange,
+		_rep_change_bad: crate::ReputationChange,
 		_transaction: Extrinsic
 	) {}
 
diff --git a/substrate/client/peerset/src/lib.rs b/substrate/client/peerset/src/lib.rs
index a243fd00bd..ab7942f60d 100644
--- a/substrate/client/peerset/src/lib.rs
+++ b/substrate/client/peerset/src/lib.rs
@@ -38,12 +38,33 @@ enum Action {
 	AddReservedPeer(PeerId),
 	RemoveReservedPeer(PeerId),
 	SetReservedOnly(bool),
-	ReportPeer(PeerId, i32),
+	ReportPeer(PeerId, ReputationChange),
 	SetPriorityGroup(String, HashSet<PeerId>),
 	AddToPriorityGroup(String, PeerId),
 	RemoveFromPriorityGroup(String, PeerId),
 }
 
+/// Shared handle to the peer set manager (PSM). Distributed around the code.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct ReputationChange {
+	/// Reputation delta.
+	pub value: i32,
+	/// Reason for reputation change.
+	pub reason: &'static str,
+}
+
+impl ReputationChange {
+	/// New reputation change with given delta and reason.
+	pub const fn new(value: i32, reason: &'static str) -> ReputationChange {
+		ReputationChange { value, reason }
+	}
+
+	/// New reputation change that forces minimum possible reputation.
+	pub const fn new_fatal(reason: &'static str) -> ReputationChange {
+		ReputationChange { value: i32::min_value(), reason }
+	}
+}
+
 /// Shared handle to the peer set manager (PSM). Distributed around the code.
 #[derive(Debug, Clone)]
 pub struct PeersetHandle {
@@ -75,7 +96,7 @@ impl PeersetHandle {
 	}
 
 	/// Reports an adjustment to the reputation of the given peer.
-	pub fn report_peer(&self, peer_id: PeerId, score_diff: i32) {
+	pub fn report_peer(&self, peer_id: PeerId, score_diff: ReputationChange) {
 		let _ = self.tx.unbounded_send(Action::ReportPeer(peer_id, score_diff));
 	}
 
@@ -258,20 +279,27 @@ impl Peerset {
 		self.alloc_slots();
 	}
 
-	fn on_report_peer(&mut self, peer_id: PeerId, score_diff: i32) {
+	fn on_report_peer(&mut self, peer_id: PeerId, change: ReputationChange) {
 		// We want reputations to be up-to-date before adjusting them.
 		self.update_time();
 
 		match self.data.peer(&peer_id) {
 			peersstate::Peer::Connected(mut peer) => {
-				peer.add_reputation(score_diff);
+				peer.add_reputation(change.value);
 				if peer.reputation() < BANNED_THRESHOLD {
+					debug!(target: "peerset", "Report {}: {:+} to {}. Reason: {}, Disconnecting",
+						peer_id, change.value, peer.reputation(), change.reason
+					);
 					peer.disconnect();
 					self.message_queue.push_back(Message::Drop(peer_id));
+				} else {
+					trace!(target: "peerset", "Report {}: {:+} to {}. Reason: {}",
+						peer_id, change.value, peer.reputation(), change.reason
+					);
 				}
 			},
-			peersstate::Peer::NotConnected(mut peer) => peer.add_reputation(score_diff),
-			peersstate::Peer::Unknown(peer) => peer.discover().add_reputation(score_diff),
+			peersstate::Peer::NotConnected(mut peer) => peer.add_reputation(change.value),
+			peersstate::Peer::Unknown(peer) => peer.discover().add_reputation(change.value),
 		}
 	}
 
@@ -293,7 +321,7 @@ impl Peerset {
 		// takes `ln(0.5) / ln(k)` seconds to reduce the reputation by half. Use this formula to
 		// empirically determine a value of `k` that looks correct.
 		for _ in 0..secs_diff {
-			for peer in self.data.peers().cloned().collect::<Vec<_>>() {
+			for peer_id in self.data.peers().cloned().collect::<Vec<_>>() {
 				// We use `k = 0.98`, so we divide by `50`. With that value, it takes 34.3 seconds
 				// to reduce the reputation by half.
 				fn reput_tick(reput: i32) -> i32 {
@@ -305,13 +333,21 @@ impl Peerset {
 					}
 					reput.saturating_sub(diff)
 				}
-				match self.data.peer(&peer) {
-					peersstate::Peer::Connected(mut peer) =>
-						peer.set_reputation(reput_tick(peer.reputation())),
-					peersstate::Peer::NotConnected(mut peer) =>
-						peer.set_reputation(reput_tick(peer.reputation())),
+				match self.data.peer(&peer_id) {
+					peersstate::Peer::Connected(mut peer) => {
+						let before = peer.reputation();
+						let after = reput_tick(before);
+						trace!(target: "peerset", "Fleeting {}: {} -> {}", peer_id, before, after);
+						peer.set_reputation(after)
+					}
+					peersstate::Peer::NotConnected(mut peer) => {
+						let before = peer.reputation();
+						let after = reput_tick(before);
+						trace!(target: "peerset", "Fleeting {}: {} -> {}", peer_id, before, after);
+						peer.set_reputation(after)
+					}
 					peersstate::Peer::Unknown(_) => unreachable!("We iterate over known peers; qed")
-				}
+				};
 			}
 		}
 	}
@@ -432,7 +468,7 @@ impl Peerset {
 	}
 
 	/// Reports an adjustment to the reputation of the given peer.
-	pub fn report_peer(&mut self, peer_id: PeerId, score_diff: i32) {
+	pub fn report_peer(&mut self, peer_id: PeerId, score_diff: ReputationChange) {
 		// We don't immediately perform the adjustments in order to have state consistency. We
 		// don't want the reporting here to take priority over messages sent using the
 		// `PeersetHandle`.
@@ -510,7 +546,7 @@ impl Stream for Peerset {
 mod tests {
 	use libp2p::PeerId;
 	use futures::prelude::*;
-	use super::{PeersetConfig, Peerset, Message, IncomingIndex, BANNED_THRESHOLD};
+	use super::{PeersetConfig, Peerset, Message, IncomingIndex, ReputationChange, BANNED_THRESHOLD};
 	use std::{pin::Pin, task::Poll, thread, time::Duration};
 
 	fn assert_messages(mut peerset: Peerset, messages: Vec<Message>) -> Peerset {
@@ -620,7 +656,7 @@ mod tests {
 
 		// We ban a node by setting its reputation under the threshold.
 		let peer_id = PeerId::random();
-		handle.report_peer(peer_id.clone(), BANNED_THRESHOLD - 1);
+		handle.report_peer(peer_id.clone(), ReputationChange::new(BANNED_THRESHOLD - 1, ""));
 
 		let fut = futures::future::poll_fn(move |cx| {
 			// We need one polling for the message to be processed.
diff --git a/substrate/client/peerset/tests/fuzz.rs b/substrate/client/peerset/tests/fuzz.rs
index 604bbcc831..55d8fabbad 100644
--- a/substrate/client/peerset/tests/fuzz.rs
+++ b/substrate/client/peerset/tests/fuzz.rs
@@ -19,7 +19,7 @@ use libp2p::PeerId;
 use rand::distributions::{Distribution, Uniform, WeightedIndex};
 use rand::seq::IteratorRandom;
 use std::{collections::HashMap, collections::HashSet, iter, pin::Pin, task::Poll};
-use sc_peerset::{IncomingIndex, Message, PeersetConfig, Peerset};
+use sc_peerset::{IncomingIndex, Message, PeersetConfig, Peerset, ReputationChange};
 
 #[test]
 fn run() {
@@ -97,7 +97,7 @@ fn test_once() {
 				// If we generate 2, adjust a random reputation.
 				2 => if let Some(id) = known_nodes.iter().choose(&mut rng) {
 					let val = Uniform::new_inclusive(i32::min_value(), i32::max_value()).sample(&mut rng);
-					peerset_handle.report_peer(id.clone(), val);
+					peerset_handle.report_peer(id.clone(), ReputationChange::new(val, ""));
 				}
 
 				// If we generate 3, disconnect from a random node.
diff --git a/substrate/client/service/src/lib.rs b/substrate/client/service/src/lib.rs
index 1a86e05b88..8e2be43965 100644
--- a/substrate/client/service/src/lib.rs
+++ b/substrate/client/service/src/lib.rs
@@ -629,8 +629,8 @@ where
 		&self,
 		report_handle: ReportHandle,
 		who: PeerId,
-		reputation_change_good: i32,
-		reputation_change_bad: i32,
+		reputation_change_good: network::ReputationChange,
+		reputation_change_bad: network::ReputationChange,
 		transaction: B::Extrinsic
 	) {
 		if !self.imports_external_transactions {