diff --git a/FreeRTOS-Plus/Demo/FreeRTOS_Plus_TCP_Echo_Posix/FreeRTOSIPConfig.h b/FreeRTOS-Plus/Demo/FreeRTOS_Plus_TCP_Echo_Posix/FreeRTOSIPConfig.h
index 517f237b69..378ac23695 100644
--- a/FreeRTOS-Plus/Demo/FreeRTOS_Plus_TCP_Echo_Posix/FreeRTOSIPConfig.h
+++ b/FreeRTOS-Plus/Demo/FreeRTOS_Plus_TCP_Echo_Posix/FreeRTOSIPConfig.h
@@ -41,10 +41,24 @@
 extern void vLoggingPrintf( const char * pcFormatString,
                             ... );
 
+/* Set to 1 to enable IPv4. */
+#define ipconfigUSE_IPv4                    ( 1 )
+
+/* Set to 1 to enable IPv6. */
+#define ipconfigUSE_IPv6                    ( 1 )
+
+/* Set to 0 to disable backward compatible. */
+#define ipconfigIPv4_BACKWARD_COMPATIBLE    0
+
+/* Set to 0 to disable compatible for multiple end-points/interfaces.
+ * Only one interface/end-point is allowed to use when ipconfigCOMPATIBLE_WITH_SINGLE
+ * is set to 1. */
+#define ipconfigCOMPATIBLE_WITH_SINGLE      0
+
 /* Set to 1 to print out debug messages. If ipconfigHAS_DEBUG_PRINTF is set to
  * 1 then FreeRTOS_debug_printf should be defined to the function used to print
  * out the debugging messages. */
-#define ipconfigHAS_DEBUG_PRINTF    1
+#define ipconfigHAS_DEBUG_PRINTF            1
 #if ( ipconfigHAS_DEBUG_PRINTF == 1 )
     #define FreeRTOS_debug_printf( X )    vLoggingPrintf X
 #endif
diff --git a/FreeRTOS-Plus/Demo/FreeRTOS_Plus_TCP_Echo_Posix/TCPEchoClient_SingleTasks.c b/FreeRTOS-Plus/Demo/FreeRTOS_Plus_TCP_Echo_Posix/TCPEchoClient_SingleTasks.c
index 766416bf2e..c52ad4a4db 100644
--- a/FreeRTOS-Plus/Demo/FreeRTOS_Plus_TCP_Echo_Posix/TCPEchoClient_SingleTasks.c
+++ b/FreeRTOS-Plus/Demo/FreeRTOS_Plus_TCP_Echo_Posix/TCPEchoClient_SingleTasks.c
@@ -215,7 +215,7 @@
                     pcTransmittedString[ strlen( pcTransmittedString ) ] = '-';
                     ulTxCount++;
 
-                    printf( "\n\tSending %d bytes of data to the echo server\n", lStringLength );
+                    printf( "\n\tSending %ld bytes of data to the echo server\n", lStringLength );
                     /* Send the string to the socket. */
                     lTransmitted = FreeRTOS_send( xSocket,                        /* The socket being sent to. */
                                                   ( void * ) pcTransmittedString, /* The data being sent. */
diff --git a/FreeRTOS-Plus/Demo/FreeRTOS_Plus_TCP_Echo_Posix/main_networking.c b/FreeRTOS-Plus/Demo/FreeRTOS_Plus_TCP_Echo_Posix/main_networking.c
index dca13ca8c5..e89b36f634 100644
--- a/FreeRTOS-Plus/Demo/FreeRTOS_Plus_TCP_Echo_Posix/main_networking.c
+++ b/FreeRTOS-Plus/Demo/FreeRTOS_Plus_TCP_Echo_Posix/main_networking.c
@@ -161,9 +161,9 @@ void main_tcp_echo_client_tasks( void )
 
 #if defined( ipconfigIPv4_BACKWARD_COMPATIBLE ) && ( ipconfigIPv4_BACKWARD_COMPATIBLE == 0 )
 
-    extern NetworkInterface_t * pxFillInterfaceDescriptor( BaseType_t xEMACIndex,
-                                                      NetworkInterface_t * pxInterface );
-    pxFillInterfaceDescriptor( 0, &( xInterfaces[ 0 ] ) );
+    extern NetworkInterface_t * pxLibslirp_FillInterfaceDescriptor( BaseType_t xEMACIndex,
+                                                                    NetworkInterface_t * pxInterface );
+    pxLibslirp_FillInterfaceDescriptor( 0, &( xInterfaces[ 0 ] ) );
 
     /* === End-point 0 === */
     FreeRTOS_FillEndPoint( &( xInterfaces[ 0 ] ), &( xEndPoints [ 0 ] ), ucIPAddress, ucNetMask, ucGatewayAddress, ucDNSServerAddress, ucMACAddress );
@@ -202,7 +202,7 @@ void main_tcp_echo_client_tasks( void )
  * events are only received if implemented in the MAC driver. */
 #if defined( ipconfigIPv4_BACKWARD_COMPATIBLE ) && ( ipconfigIPv4_BACKWARD_COMPATIBLE == 0 )
     void vApplicationIPNetworkEventHook_Multi( eIPCallbackEvent_t eNetworkEvent,
-                                                   struct xNetworkEndPoint * pxEndPoint )
+                                               struct xNetworkEndPoint * pxEndPoint )
 #else
     void vApplicationIPNetworkEventHook( eIPCallbackEvent_t eNetworkEvent )
 #endif /* defined( ipconfigIPv4_BACKWARD_COMPATIBLE ) && ( ipconfigIPv4_BACKWARD_COMPATIBLE == 0 ) */
@@ -279,6 +279,7 @@ static void prvMiscInitialisation( void )
 {
     time_t xTimeNow;
     uint32_t ulRandomNumbers[ 4 ];
+
     /* Seed the random number generator. */
     time( &xTimeNow );
     FreeRTOS_debug_printf( ( "Seed for randomiser: %lu\n", xTimeNow ) );
@@ -313,10 +314,10 @@ static void prvMiscInitialisation( void )
 
     #if defined( ipconfigIPv4_BACKWARD_COMPATIBLE ) && ( ipconfigIPv4_BACKWARD_COMPATIBLE == 0 )
         BaseType_t xApplicationDNSQueryHook_Multi( struct xNetworkEndPoint * pxEndPoint,
-                                                            const char * pcName )
+                                                   const char * pcName )
     #else
         BaseType_t xApplicationDNSQueryHook( const char * pcName )
-    #endif /* defined( ipconfigIPv4_BACKWARD_COMPATIBLE ) && ( ipconfigIPv4_BACKWARD_COMPATIBLE == 0 ) */    
+    #endif /* defined( ipconfigIPv4_BACKWARD_COMPATIBLE ) && ( ipconfigIPv4_BACKWARD_COMPATIBLE == 0 ) */
     {
         BaseType_t xReturn;
 
diff --git a/FreeRTOS-Plus/Demo/FreeRTOS_Plus_TCP_Minimal_Windows_Simulator/main.c b/FreeRTOS-Plus/Demo/FreeRTOS_Plus_TCP_Minimal_Windows_Simulator/main.c
index 62c77919a8..502877baae 100644
--- a/FreeRTOS-Plus/Demo/FreeRTOS_Plus_TCP_Minimal_Windows_Simulator/main.c
+++ b/FreeRTOS-Plus/Demo/FreeRTOS_Plus_TCP_Minimal_Windows_Simulator/main.c
@@ -170,9 +170,9 @@ int main( void )
 #if defined( ipconfigIPv4_BACKWARD_COMPATIBLE ) && ( ipconfigIPv4_BACKWARD_COMPATIBLE == 0 )
 
 #ifdef ipconfigUSE_LIBSLIRP
-    extern NetworkInterface_t* pxFillInterfaceDescriptor(BaseType_t xEMACIndex,
+    extern NetworkInterface_t* pxLibslirp_FillInterfaceDescriptor(BaseType_t xEMACIndex,
         NetworkInterface_t * pxInterface);
-    pxFillInterfaceDescriptor( 0, &( xInterfaces[ 0 ] ) );
+    pxLibslirp_FillInterfaceDescriptor( 0, &( xInterfaces[ 0 ] ) );
 #else
     pxWinPcap_FillInterfaceDescriptor( 0, &( xInterfaces[ 0 ] ) );
 #endif
diff --git a/FreeRTOS-Plus/Source/FreeRTOS-Plus-TCP b/FreeRTOS-Plus/Source/FreeRTOS-Plus-TCP
index 67b9e1c281..40c16fef7b 160000
--- a/FreeRTOS-Plus/Source/FreeRTOS-Plus-TCP
+++ b/FreeRTOS-Plus/Source/FreeRTOS-Plus-TCP
@@ -1 +1 @@
-Subproject commit 67b9e1c2813792625500f9e8c091822b325f3fe7
+Subproject commit 40c16fef7b3380982a8e6517654272cca5a9dc0a
diff --git a/FreeRTOS-Plus/VisualStudio_StaticProjects/FreeRTOS+TCP/plus_tcp_hooks_winsim.c b/FreeRTOS-Plus/VisualStudio_StaticProjects/FreeRTOS+TCP/plus_tcp_hooks_winsim.c
index 373a9a087c..8f689da522 100644
--- a/FreeRTOS-Plus/VisualStudio_StaticProjects/FreeRTOS+TCP/plus_tcp_hooks_winsim.c
+++ b/FreeRTOS-Plus/VisualStudio_StaticProjects/FreeRTOS+TCP/plus_tcp_hooks_winsim.c
@@ -205,9 +205,9 @@ void vPlatformInitIpStack( void )
 #if defined( ipconfigIPv4_BACKWARD_COMPATIBLE ) && ( ipconfigIPv4_BACKWARD_COMPATIBLE == 0 )
     /* Initialise the interface descriptor for WinPCap. */
     #ifdef ipconfigUSE_LIBSLIRP
-        extern NetworkInterface_t* pxFillInterfaceDescriptor(BaseType_t xEMACIndex,
+        extern NetworkInterface_t* pxLibslirp_FillInterfaceDescriptor(BaseType_t xEMACIndex,
             NetworkInterface_t * pxInterface);
-        pxFillInterfaceDescriptor( 0, &( xInterfaces[ 0 ] ) );
+        pxLibslirp_FillInterfaceDescriptor( 0, &( xInterfaces[ 0 ] ) );
     #else
         pxWinPcap_FillInterfaceDescriptor( 0, &( xInterfaces[ 0 ] ) );
     #endif
diff --git a/manifest.yml b/manifest.yml
index 5a19bfe9eb..1e61881024 100644
--- a/manifest.yml
+++ b/manifest.yml
@@ -11,7 +11,7 @@ dependencies:
       path: "FreeRTOS/Source"
 
   - name: "FreeRTOS-Plus-TCP"
-    version: "67b9e1c"
+    version: "40c16fe"
     repository:
       type: "git"
       url: "https://github.com/FreeRTOS/FreeRTOS-Plus-TCP.git"