diff --git a/libi2pd/I2NPProtocol.cpp b/libi2pd/I2NPProtocol.cpp
index b8acbcbe..4d1ab6d4 100644
--- a/libi2pd/I2NPProtocol.cpp
+++ b/libi2pd/I2NPProtocol.cpp
@@ -1,5 +1,5 @@
 /*
-* Copyright (c) 2013-2022, The PurpleI2P Project
+* Copyright (c) 2013-2023, The PurpleI2P Project
 *
 * This file is part of Purple i2pd project and licensed under BSD3
 *
@@ -392,7 +392,8 @@ namespace i2p
 							clearText + ECIES_BUILD_REQUEST_RECORD_IV_KEY_OFFSET,
 							clearText[ECIES_BUILD_REQUEST_RECORD_FLAG_OFFSET] & TUNNEL_BUILD_RECORD_GATEWAY_FLAG,
 							clearText[ECIES_BUILD_REQUEST_RECORD_FLAG_OFFSET] & TUNNEL_BUILD_RECORD_ENDPOINT_FLAG);
-					i2p::tunnel::tunnels.AddTransitTunnel (transitTunnel);
+					if (!i2p::tunnel::tunnels.AddTransitTunnel (transitTunnel))
+						retCode = 30;
 				}
 				else
 					retCode = 30; // always reject with bandwidth reason (30)
@@ -590,7 +591,8 @@ namespace i2p
 						layerKey, ivKey,
 						clearText[SHORT_REQUEST_RECORD_FLAG_OFFSET] & TUNNEL_BUILD_RECORD_GATEWAY_FLAG,
 						clearText[SHORT_REQUEST_RECORD_FLAG_OFFSET] & TUNNEL_BUILD_RECORD_ENDPOINT_FLAG);
-					i2p::tunnel::tunnels.AddTransitTunnel (transitTunnel);
+					if (!i2p::tunnel::tunnels.AddTransitTunnel (transitTunnel))
+						retCode = 30;
 				}
 
 				// encrypt reply
diff --git a/libi2pd/Tunnel.cpp b/libi2pd/Tunnel.cpp
index f3b7152d..611b0ec0 100644
--- a/libi2pd/Tunnel.cpp
+++ b/libi2pd/Tunnel.cpp
@@ -1,5 +1,5 @@
 /*
-* Copyright (c) 2013-2022, The PurpleI2P Project
+* Copyright (c) 2013-2023, The PurpleI2P Project
 *
 * This file is part of Purple i2pd project and licensed under BSD3
 *
@@ -433,12 +433,16 @@ namespace tunnel
 		}
 	}
 
-	void Tunnels::AddTransitTunnel (std::shared_ptr<TransitTunnel> tunnel)
+	bool Tunnels::AddTransitTunnel (std::shared_ptr<TransitTunnel> tunnel)
 	{
 		if (m_Tunnels.emplace (tunnel->GetTunnelID (), tunnel).second)
 			m_TransitTunnels.push_back (tunnel);
 		else
+		{	
 			LogPrint (eLogError, "Tunnel: Tunnel with id ", tunnel->GetTunnelID (), " already exists");
+			return false;	
+		}		
+		return true;	
 	}
 
 	void Tunnels::Start ()
diff --git a/libi2pd/Tunnel.h b/libi2pd/Tunnel.h
index af813c81..d4fc7d5b 100644
--- a/libi2pd/Tunnel.h
+++ b/libi2pd/Tunnel.h
@@ -1,5 +1,5 @@
 /*
-* Copyright (c) 2013-2022, The PurpleI2P Project
+* Copyright (c) 2013-2023, The PurpleI2P Project
 *
 * This file is part of Purple i2pd project and licensed under BSD3
 *
@@ -210,7 +210,7 @@ namespace tunnel
 			std::shared_ptr<TunnelPool> GetExploratoryPool () const { return m_ExploratoryPool; };
 			std::shared_ptr<TunnelBase> GetTunnel (uint32_t tunnelID);
 			int GetTransitTunnelsExpirationTimeout ();
-			void AddTransitTunnel (std::shared_ptr<TransitTunnel> tunnel);
+			bool AddTransitTunnel (std::shared_ptr<TransitTunnel> tunnel);
 			void AddOutboundTunnel (std::shared_ptr<OutboundTunnel> newTunnel);
 			void AddInboundTunnel (std::shared_ptr<InboundTunnel> newTunnel);
 			std::shared_ptr<InboundTunnel> CreateInboundTunnel (std::shared_ptr<TunnelConfig> config, std::shared_ptr<TunnelPool> pool, std::shared_ptr<OutboundTunnel> outboundTunnel);