diff --git a/src/network/core/tcp.cpp b/src/network/core/tcp.cpp
--- a/src/network/core/tcp.cpp
+++ b/src/network/core/tcp.cpp
@@ -112,7 +112,7 @@ SendPacketsState NetworkTCPSocketHandler
 			if (!err.WouldBlock()) {
 				/* Something went wrong.. close client! */
 				if (!closing_down) {
-					DEBUG(net, 0, "Send failed: %s", err.AsString());
+					Debug(net, 0, "Send failed: {}", err.AsString());
 					this->CloseConnection();
 				}
 				return SPS_CLOSED;
@@ -161,7 +161,7 @@ Packet *NetworkTCPSocketHandler::Receive
 				NetworkError err = NetworkError::GetLast();
 				if (!err.WouldBlock()) {
 					/* Something went wrong... */
-					if (!err.IsConnectionReset()) DEBUG(net, 0, "Recv failed: %s", err.AsString());
+					if (!err.IsConnectionReset()) Debug(net, 0, "Recv failed: {}", err.AsString());
 					this->CloseConnection();
 					return nullptr;
 				}
@@ -189,7 +189,7 @@ Packet *NetworkTCPSocketHandler::Receive
 			NetworkError err = NetworkError::GetLast();
 			if (!err.WouldBlock()) {
 				/* Something went wrong... */
-				if (!err.IsConnectionReset()) DEBUG(net, 0, "Recv failed: %s", err.AsString());
+				if (!err.IsConnectionReset()) Debug(net, 0, "Recv failed: {}", err.AsString());
 				this->CloseConnection();
 				return nullptr;
 			}