diff --git a/source/FreeRTOS_IPv6.c b/source/FreeRTOS_IPv6.c
index 33076e6e9..701f8ef2f 100644
--- a/source/FreeRTOS_IPv6.c
+++ b/source/FreeRTOS_IPv6.c
@@ -132,7 +132,9 @@ const struct xIPv6_Address FreeRTOS_in6addr_loopback = { { 0, 0, 0, 0, 0, 0, 0,
             /* Check if the complete IPv6-header plus protocol data have been transferred: */
             usPayloadLength = FreeRTOS_ntohs( pxIPv6Packet->xIPHeader.usPayloadLength );
 
-            if( uxBufferLength != ( size_t ) ( ipSIZE_OF_ETH_HEADER + ipSIZE_OF_IPv6_HEADER + ( size_t ) usPayloadLength ) )
+            /* Since network interface might put some data in the network buffer,
+             * we allow buffer length to be greater than necessary. */
+            if( uxBufferLength < ( size_t ) ( ipSIZE_OF_ETH_HEADER + ipSIZE_OF_IPv6_HEADER + ( size_t ) usPayloadLength ) )
             {
                 DEBUG_SET_TRACE_VARIABLE( xLocation, 4 );
                 break;
diff --git a/test/unit-test/FreeRTOS_IPv6_ConfigDriverCheckChecksum/FreeRTOS_IPv6_ConfigDriverCheckChecksum_stubs.c b/test/unit-test/FreeRTOS_IPv6_ConfigDriverCheckChecksum/FreeRTOS_IPv6_ConfigDriverCheckChecksum_stubs.c
index 2895fb0e6..ea4581a1f 100644
--- a/test/unit-test/FreeRTOS_IPv6_ConfigDriverCheckChecksum/FreeRTOS_IPv6_ConfigDriverCheckChecksum_stubs.c
+++ b/test/unit-test/FreeRTOS_IPv6_ConfigDriverCheckChecksum/FreeRTOS_IPv6_ConfigDriverCheckChecksum_stubs.c
@@ -51,6 +51,9 @@ const IPv6_Address_t xIPAddressTen = { 0x20, 0x01, 0x12, 0x34, 0x56, 0x78, 0x00,
 /* MAC Address for endpoint. */
 const uint8_t ucMACAddress[ ipMAC_ADDRESS_LENGTH_BYTES ] = { 0xab, 0xcd, 0xef, 0x11, 0x22, 0x33 };
 
+/* Default payload length in this test. */
+#define TEST_DEFAULT_PROTOCOL_PAYLOAD_LENGTH    ( 8U )
+
 /* ======================== Stub Callback Functions ========================= */
 
 NetworkEndPoint_t * prvInitializeEndpoint()
@@ -74,14 +77,14 @@ NetworkEndPoint_t * prvInitializeEndpoint()
 NetworkBufferDescriptor_t * prvInitializeNetworkDescriptor()
 {
     static NetworkBufferDescriptor_t xNetworkBuffer;
-    static uint8_t pcNetworkBuffer[ sizeof( TCPPacket_IPv6_t ) + 8U ];
+    static uint8_t pcNetworkBuffer[ sizeof( TCPPacket_IPv6_t ) + TEST_DEFAULT_PROTOCOL_PAYLOAD_LENGTH ];
     TCPPacket_IPv6_t * pxTCPPacket = ( TCPPacket_IPv6_t * ) pcNetworkBuffer;
 
     /* Initialize network buffer descriptor. */
     memset( &xNetworkBuffer, 0, sizeof( xNetworkBuffer ) );
     xNetworkBuffer.pxEndPoint = prvInitializeEndpoint();
     xNetworkBuffer.pucEthernetBuffer = ( uint8_t * ) pxTCPPacket;
-    xNetworkBuffer.xDataLength = sizeof( TCPPacket_IPv6_t ) + 8U;
+    xNetworkBuffer.xDataLength = sizeof( TCPPacket_IPv6_t ) + TEST_DEFAULT_PROTOCOL_PAYLOAD_LENGTH;
 
     /* Initialize network buffer. */
     memset( pcNetworkBuffer, 0, sizeof( pcNetworkBuffer ) );
@@ -93,7 +96,7 @@ NetworkBufferDescriptor_t * prvInitializeNetworkDescriptor()
     memcpy( pxTCPPacket->xIPHeader.xSourceAddress.ucBytes, xIPAddressTen.ucBytes, sizeof( IPv6_Address_t ) );
     memcpy( pxTCPPacket->xIPHeader.xDestinationAddress.ucBytes, xIPAddressFive.ucBytes, sizeof( IPv6_Address_t ) );
     pxTCPPacket->xIPHeader.ucVersionTrafficClass |= 6U << 4;
-    pxTCPPacket->xIPHeader.usPayloadLength = FreeRTOS_htons( sizeof( TCPHeader_t ) + 8U );
+    pxTCPPacket->xIPHeader.usPayloadLength = FreeRTOS_htons( sizeof( TCPHeader_t ) + TEST_DEFAULT_PROTOCOL_PAYLOAD_LENGTH );
     pxTCPPacket->xIPHeader.ucNextHeader = ipPROTOCOL_TCP;
 
     return &xNetworkBuffer;
diff --git a/test/unit-test/FreeRTOS_IPv6_ConfigDriverCheckChecksum/FreeRTOS_IPv6_ConfigDriverCheckChecksum_utest.c b/test/unit-test/FreeRTOS_IPv6_ConfigDriverCheckChecksum/FreeRTOS_IPv6_ConfigDriverCheckChecksum_utest.c
index 8404b9ba2..00aef5bd7 100644
--- a/test/unit-test/FreeRTOS_IPv6_ConfigDriverCheckChecksum/FreeRTOS_IPv6_ConfigDriverCheckChecksum_utest.c
+++ b/test/unit-test/FreeRTOS_IPv6_ConfigDriverCheckChecksum/FreeRTOS_IPv6_ConfigDriverCheckChecksum_utest.c
@@ -145,8 +145,8 @@ void test_prvAllowIPPacketIPv6_xCheckIPv6SizeFields_wrong_ip_length()
     NetworkBufferDescriptor_t * pxNetworkBuffer = prvInitializeNetworkDescriptor();
     IPPacket_IPv6_t * pxIPPacket = ( IPPacket_IPv6_t * ) pxNetworkBuffer->pucEthernetBuffer;
 
-    /* Modify the length in IP header */
-    pxIPPacket->xIPHeader.usPayloadLength = FreeRTOS_htons( sizeof( TCPHeader_t ) );
+    /* Modify the length in IP header to be greater than data length. */
+    pxIPPacket->xIPHeader.usPayloadLength = FreeRTOS_htons( sizeof( TCPHeader_t ) + TEST_DEFAULT_PROTOCOL_PAYLOAD_LENGTH + 1U );
 
     eResult = prvAllowIPPacketIPv6( &pxIPPacket->xIPHeader, pxNetworkBuffer, 0U );
     TEST_ASSERT_EQUAL( eReleaseBuffer, eResult );