diff --git a/NetworkPkg/IScsiDxe/IScsiDhcp.c b/NetworkPkg/IScsiDxe/IScsiDhcp.c
index 7ce9bf5750..afa8a86cd4 100644
--- a/NetworkPkg/IScsiDxe/IScsiDhcp.c
+++ b/NetworkPkg/IScsiDxe/IScsiDhcp.c
@@ -122,7 +122,7 @@ IScsiDhcpExtractRootPath (
   //
   if ((!NET_IS_DIGIT (*(Field->Str))) && (*(Field->Str) != '[')) {
     ConfigNvData->DnsMode = TRUE;
-    if (Field->Len > sizeof (ConfigNvData->TargetUrl)) {
+    if ((Field->Len + 2) > sizeof (ConfigNvData->TargetUrl)) {
       return EFI_INVALID_PARAMETER;
     }
     CopyMem (&ConfigNvData->TargetUrl, Field->Str, Field->Len);
diff --git a/NetworkPkg/IScsiDxe/IScsiDhcp6.c b/NetworkPkg/IScsiDxe/IScsiDhcp6.c
index 86a872adec..691650b733 100644
--- a/NetworkPkg/IScsiDxe/IScsiDhcp6.c
+++ b/NetworkPkg/IScsiDxe/IScsiDhcp6.c
@@ -161,7 +161,7 @@ IScsiDhcp6ExtractRootPath (
   // Server name is expressed as domain name, just save it.
   //
   if (ConfigNvData->DnsMode) {
-    if (Field->Len > sizeof (ConfigNvData->TargetUrl)) {
+    if ((Field->Len + 2) > sizeof (ConfigNvData->TargetUrl)) {
       return EFI_INVALID_PARAMETER;
     }
     CopyMem (&ConfigNvData->TargetUrl, Field->Str, Field->Len);