diff --git a/NetworkPkg/Dhcp6Dxe/Dhcp6Utility.c b/NetworkPkg/Dhcp6Dxe/Dhcp6Utility.c
index e4e0725622..f38e3ee3fe 100644
--- a/NetworkPkg/Dhcp6Dxe/Dhcp6Utility.c
+++ b/NetworkPkg/Dhcp6Dxe/Dhcp6Utility.c
@@ -924,6 +924,11 @@ Dhcp6AppendIaOption (
     *PacketCursor += sizeof (T2);
   }
 
+  //
+  // Update the packet length
+  //
+  Packet->Length += BytesNeeded;
+
   //
   // Fill all the addresses belong to the Ia
   //
@@ -935,11 +940,6 @@ Dhcp6AppendIaOption (
     }
   }
 
-  //
-  // Update the packet length
-  //
-  Packet->Length += BytesNeeded;
-
   //
   // Fill the value of Ia option length
   //