diff --git a/lib/runcpm/abstraction_fujinet.h b/lib/runcpm/abstraction_fujinet.h
index 4460b781a..257bced8d 100644
--- a/lib/runcpm/abstraction_fujinet.h
+++ b/lib/runcpm/abstraction_fujinet.h
@@ -643,10 +643,18 @@ uint8_t bios_tcpListen(uint16_t port)
 	}
 
 	server = new fnTcpServer(port,1);
-	server->begin(port);
 
-	Debug_printf("bios_tcpListen - Now listening on port %u\r\n", port);
-	return server != nullptr;
+	int res = server->begin(port);
+	if (res == 0)
+	{
+		Debug_printf("bios_tcpListen - failed to open port %u\nError (%d): %s\r\n", port, errno, strerror(errno));
+		return true;
+	}
+	else
+	{
+		Debug_printf("bios_tcpListen - Now listening on port %u\r\n", port);
+		return false;
+	}
 }
 
 uint8_t bios_tcpAvailable(void)
diff --git a/lib/runcpm/abstraction_fujinet_apple2.h b/lib/runcpm/abstraction_fujinet_apple2.h
index 8a0476487..df37dccf0 100644
--- a/lib/runcpm/abstraction_fujinet_apple2.h
+++ b/lib/runcpm/abstraction_fujinet_apple2.h
@@ -639,10 +639,17 @@ uint8_t bios_tcpListen(uint16_t port)
 	}
 
 	server = new fnTcpServer(port,1);
-	server->begin(port);
-
-	Debug_printf("bios_tcpListen - Now listening on port %u\r\n", port);
-	return server != nullptr;
+	int res = server->begin(port);
+	if (res == 0)
+	{
+		Debug_printf("bios_tcpListen - failed to open port %u\nError (%d): %s\r\n", port, errno, strerror(errno));
+		return true;
+	}
+	else
+	{
+		Debug_printf("bios_tcpListen - Now listening on port %u\r\n", port);
+		return false;
+	}
 }
 
 uint8_t bios_tcpAvailable(void)
diff --git a/lib/tcpip/fnTcpServer.cpp b/lib/tcpip/fnTcpServer.cpp
index 907822a44..126ff6ef8 100644
--- a/lib/tcpip/fnTcpServer.cpp
+++ b/lib/tcpip/fnTcpServer.cpp
@@ -8,10 +8,13 @@
 
 
 // Configures a listening TCP socket on given port
-void fnTcpServer::begin(uint16_t port)
+// Returns 0 for error, 1 for success.
+int fnTcpServer::begin(uint16_t port)
 {
-    if (_listening)
-        return;
+    if (_listening) {
+        Debug_println("TCP Server already listening. Aborting.");
+        return 0;
+    }
 
     if (port)
         _port = port;
@@ -21,7 +24,7 @@ void fnTcpServer::begin(uint16_t port)
     if (_sockfd < 0)
     {
         Debug_printf("fnTcpServer::begin failed to allocate socket, err %d\r\n", errno);
-        return;
+        return 0;
     }
 
     // Bind socket to our interface
@@ -32,13 +35,14 @@ void fnTcpServer::begin(uint16_t port)
     if (bind(_sockfd, (struct sockaddr *)&server, sizeof(server)) < 0)
     {
         Debug_printf("fnTcpServer::begin failed to bind socket, err %d\r\n", errno);
-        return;
+        return 0;
     }
 
     int enable = 1;
     if (setsockopt(_sockfd, SOL_SOCKET, SO_REUSEADDR, &enable, sizeof(int)) < 0)
     {
-        Debug_printf("fnTcpServer::begin failed to set SO_REUSEADDR, err %d", errno);
+        Debug_printf("fnTcpServer::begin failed to set SO_REUSEADDR, err %d\r\n", errno);
+        return 0;
     }
 
     Debug_printf("Max clients is currently %u\r\n",_max_clients);
@@ -47,15 +51,22 @@ void fnTcpServer::begin(uint16_t port)
     if (listen(_sockfd, _max_clients) < 0)
     {
         Debug_printf("fnTcpServer::begin failed to listen on socket, err %d\r\n", errno);
-        return;
+        return 0;
     }
 
     // Switch to non-blocking mode
-    fcntl(_sockfd, F_SETFL, O_NONBLOCK);
+    if (fcntl(_sockfd, F_SETFL, O_NONBLOCK) < 0)
+    {
+        Debug_printf("fnTcpServer::begin failed to set non-blocking mode. Closing down server. err %d\n", errno);
+        stop();
+        return 0;
+    }
 
     _listening = true;
     _noDelay = false;
     _accepted_sockfd = -1;
+    Debug_printf("TCP Server now listening on port %d.\n", _port);
+    return 1;
 }
 
 // Returns true if a client has connected to the socket
diff --git a/lib/tcpip/fnTcpServer.h b/lib/tcpip/fnTcpServer.h
index f850aadc0..9ec638145 100644
--- a/lib/tcpip/fnTcpServer.h
+++ b/lib/tcpip/fnTcpServer.h
@@ -21,7 +21,7 @@ class fnTcpServer
     fnTcpServer(uint16_t port=80, uint8_t max_clients=4): _port(port), _max_clients(max_clients){}
     ~fnTcpServer(){ stop(); }
 
-    void begin(uint16_t port=0);
+    int begin(uint16_t port=0);
 
     fnTcpClient accept(){ return available(); }
     void setNoDelay(bool nodelay) { _noDelay = nodelay; };