diff --git a/source/portable/NetworkInterface/STM32/NetworkInterface.c b/source/portable/NetworkInterface/STM32/NetworkInterface.c
index 8bf5333a9..0d088a74d 100644
--- a/source/portable/NetworkInterface/STM32/NetworkInterface.c
+++ b/source/portable/NetworkInterface/STM32/NetworkInterface.c
@@ -602,6 +602,7 @@ static BaseType_t prvNetworkInterfaceOutput( NetworkInterface_t * pxInterface,
             break;
         }
 
+        // ETH_TxPacketConfigTypeDef
         ETH_TxPacketConfig xTxConfig =
         {
             .CRCPadCtrl = ETH_CRC_PAD_INSERT,