diff --git a/MdePkg/Include/Protocol/Ip4.h b/MdePkg/Include/Protocol/Ip4.h
index 246104dcc5..15ec514d80 100644
--- a/MdePkg/Include/Protocol/Ip4.h
+++ b/MdePkg/Include/Protocol/Ip4.h
@@ -143,6 +143,10 @@ typedef struct {
   ///
   BOOLEAN                 IsStarted;
   ///
+  /// The maximum packet size, in bytes, of the packet which the upper layer driver could feed.
+  ///
+  UINT32                  MaxPacketSize;
+  ///
   /// Current configuration settings.
   ///
   EFI_IP4_CONFIG_DATA     ConfigData;