diff --git a/cpp/s2p/s2p_server.cpp b/cpp/s2p/s2p_server.cpp
index 2741be1c..6846fa3c 100644
--- a/cpp/s2p/s2p_server.cpp
+++ b/cpp/s2p/s2p_server.cpp
@@ -8,13 +8,11 @@
 
 #include "s2p_server.h"
 #include <cassert>
-#include <csignal>
+#include <cstring>
+#include <unistd.h>
 #include <arpa/inet.h>
 #include <netinet/in.h>
 #include <sys/socket.h>
-#include <spdlog/spdlog.h>
-
-using namespace spdlog;
 
 string S2pServer::Init(int port)
 {
@@ -23,12 +21,12 @@ string S2pServer::Init(int port)
 
     server_socket = socket(PF_INET, SOCK_STREAM, 0);
     if (server_socket == -1) {
-        return fmt::format("Can't create server socket: {}", strerror(errno));
+        return "Can't create server socket: " + string(strerror(errno));
     }
 
     if (const int enable = 1; setsockopt(server_socket, SOL_SOCKET, SO_REUSEADDR, &enable, sizeof(enable)) == -1) {
         Stop();
-        return fmt::format("Can't reuse socket: {}", strerror(errno));
+        return "Can't reuse socket: " + string(strerror(errno));
     }
 
     sockaddr_in server = { };
@@ -38,7 +36,7 @@ string S2pServer::Init(int port)
     if (bind(server_socket, reinterpret_cast<const sockaddr*>(&server), // NOSONAR bit_cast is not supported by the bullseye compiler
         static_cast<socklen_t>(sizeof(sockaddr_in))) < 0) {
         Stop();
-        return fmt::format("Port {} is in use, s2p may already be running", port);
+        return "Port " + to_string(port) + " is in use, s2p may already be running";
     }
 
     if (listen(server_socket, 2) == -1) {