diff --git a/schemas/legacy.json b/schemas/legacy.json
index 15326b5..601c52c 100644
--- a/schemas/legacy.json
+++ b/schemas/legacy.json
@@ -721,7 +721,8 @@
                 "type": "object"
             },
             "ConnectsToType": {
-                "type": "string"
+                "type": "string",
+                "const": "MB Upstream Port"
             },
             "CpuID": {
                 "type": "number"