diff --git a/client/network/src/service.rs b/client/network/src/service.rs
index 78197e68e7793..2297fe6a52f72 100644
--- a/client/network/src/service.rs
+++ b/client/network/src/service.rs
@@ -672,13 +672,14 @@ impl<B: BlockT + 'static, H: ExHashT> NetworkService<B, H> {
 
 	/// Adds a `PeerId` and its address as reserved. The string should encode the address
 	/// and peer ID of the remote node.
+	///
+	/// Returns an `Err` if the given string is not a valid multiaddress
+	/// or contains an invalid peer ID (which includes the local peer ID).
 	pub fn add_reserved_peer(&self, peer: String) -> Result<(), String> {
 		let (peer_id, addr) = parse_str_addr(&peer).map_err(|e| format!("{:?}", e))?;
 		// Make sure the local peer ID is never added to the PSM.
-		// We don't treat this as an error, because the caller may
-		// not know the peer ID beforehand.
-		if peer == &self.local_peer_id {
-			return Ok(())
+		if peer_id == self.local_peer_id {
+			return Err("Local peer ID cannot be added as a reserved peer.".to_string())
 		}
 		self.peerset.add_reserved_peer(peer_id.clone());
 		let _ = self
@@ -700,18 +701,21 @@ impl<B: BlockT + 'static, H: ExHashT> NetworkService<B, H> {
 	}
 
 	/// Modify a peerset priority group.
+	///
+	/// Returns an `Err` if one of the given addresses contains an invalid
+	/// peer ID (which includes the local peer ID).
 	pub fn set_priority_group(&self, group_id: String, peers: HashSet<Multiaddr>) -> Result<(), String> {
 		let peers = peers.into_iter()
-			.map(|p| parse_addr(p).map_err(|e| format!("{:?}", e)))
-			.filter(|r|
-				// Make sure the local peer ID is never added to the PSM
-				// or added as a "known address", even if given.
-				// We don't treat this as an error, because the caller may
-				// not know the peer ID beforehand.
-				if let Ok((peer, _)) = r {
-					peer != &self.local_peer_id
-				} else {
-					true // keep all errors
+			.map(|p| match parse_addr(p) {
+				Err(e) => Err(format!("{:?}", e)),
+				Ok((peer, addr)) =>
+					// Make sure the local peer ID is never added to the PSM
+					// or added as a "known address", even if given.
+					if peer == self.local_peer_id {
+						Err("Local peer ID in priority group.".to_string())
+					} else {
+						Ok((peer, addr))
+					}
 				})
 			.collect::<Result<Vec<(PeerId, Multiaddr)>, String>>()?;