diff --git a/sync_loop.go b/sync_loop.go
index 72f0b2e..1e1131d 100644
--- a/sync_loop.go
+++ b/sync_loop.go
@@ -60,13 +60,18 @@ func runChainSyncOnce(ctx context.Context, blockchain *chain.Chain, chainConfig
 	}
 	defer conn.Close()
 
-	levinConnection := levin.NewConnection(conn)
+	p2pConn := levin.NewConnection(conn)
 
 	var peerIDBytes [8]byte
-	rand.Read(peerIDBytes[:])
+	if _, err := rand.Read(peerIDBytes[:]); err != nil {
+		return coreerr.E("runChainSyncOnce", "generate peer id", err)
+	}
 	peerID := binary.LittleEndian.Uint64(peerIDBytes[:])
 
-	localHeight, _ := blockchain.Height()
+	localHeight, err := blockchain.Height()
+	if err != nil {
+		return coreerr.E("runChainSyncOnce", "get local height", err)
+	}
 
 	handshakeRequest := p2p.HandshakeRequest{
 		NodeData: p2p.NodeData{
@@ -85,11 +90,11 @@ func runChainSyncOnce(ctx context.Context, blockchain *chain.Chain, chainConfig
 	if err != nil {
 		return coreerr.E("runChainSyncOnce", "encode handshake", err)
 	}
-	if err := levinConnection.WritePacket(p2p.CommandHandshake, payload, true); err != nil {
+	if err := p2pConn.WritePacket(p2p.CommandHandshake, payload, true); err != nil {
 		return coreerr.E("runChainSyncOnce", "write handshake", err)
 	}
 
-	packetHeader, packetData, err := levinConnection.ReadPacket()
+	packetHeader, packetData, err := p2pConn.ReadPacket()
 	if err != nil {
 		return coreerr.E("runChainSyncOnce", "read handshake", err)
 	}
@@ -111,7 +116,7 @@ func runChainSyncOnce(ctx context.Context, blockchain *chain.Chain, chainConfig
 		ClientVersion:  config.ClientVersion,
 		NonPruningMode: true,
 	}
-	p2pConnection := chain.NewLevinP2PConn(levinConnection, handshakeResponse.PayloadData.CurrentHeight, localSyncData)
+	p2pConnection := chain.NewLevinP2PConn(p2pConn, handshakeResponse.PayloadData.CurrentHeight, localSyncData)
 
 	return blockchain.P2PSync(ctx, p2pConnection, opts)
 }