--- FreeRTOS-Plus/Source/FreeRTOS-Plus-TCP/FreeRTOS_Sockets.c	2020-09-15 03:43:02.000000000 +0100
+++ SimiaTec/VoSPI/TCPIP/FreeRTOS_Sockets.c	2020-09-28 16:42:57.238118100 +0100
@@ -134,7 +134,9 @@
  * Internal function prvSockopt_so_buffer(): sets FREERTOS_SO_SNDBUF or
  * FREERTOS_SO_RCVBUF properties of a socket.
  */
+#if( ipconfigUSE_TCP == 1 )
 static BaseType_t prvSockopt_so_buffer( FreeRTOS_Socket_t *pxSocket, int32_t lOptionName, const void *pvOptionValue );
+#endif /* ipconfigUSE_TCP == 1 */
 
 /*
  * Before creating a socket, check the validity of the parameters used
@@ -1372,6 +1374,8 @@
 
 /*-----------------------------------------------------------*/
 
+#if ipconfigUSE_TCP == 1
+
 static BaseType_t prvSockopt_so_buffer( FreeRTOS_Socket_t *pxSocket, int32_t lOptionName, const void *pvOptionValue )
 {
 uint32_t ulNewValue;
@@ -1409,6 +1413,9 @@
 
 	return xReturn;
 }
+
+#endif /* ipconfigUSE_TCP == 1 */
+
 /*-----------------------------------------------------------*/
 
 /* FreeRTOS_setsockopt calls itself, but in a very limited way,