diff --git a/beacon_api/schemas/query.json b/beacon_api/schemas/query.json
index c86b78a1..24c71f18 100644
--- a/beacon_api/schemas/query.json
+++ b/beacon_api/schemas/query.json
@@ -107,7 +107,12 @@
     "oneOf": [{
         "required": [
           "variantType"
-        ]
+        ],
+        "not": {
+          "required": [
+            "mateName"
+          ]
+        }
       },
       {
         "required": [
@@ -117,7 +122,24 @@
       {
         "required": [
           "mateName"
-        ]
+        ],
+        "not": {
+          "required": [
+            "variantType"
+          ]
+        }
+      },
+      {
+        "required": [
+          "mateName",
+          "variantType"
+        ],
+        "properties": {
+          "variantType": {
+            "type": "string",
+            "enum": ["BND"]
+          }
+        }
       }
     ]
   }, {
diff --git a/docs/optionals.rst b/docs/optionals.rst
index 69fcf88b..42acf8d4 100644
--- a/docs/optionals.rst
+++ b/docs/optionals.rst
@@ -106,6 +106,10 @@ Currently querying for a ``BND`` using ``startMin``, ``startMax`` and ``endMin``
 with ``variantType=BND`` has the response illustrated below.
 Fixed ``start`` and ``end`` can be utilised, as well as ``mateName`` as depicted above.
 
+.. note:: By default when using ``mateName``, ``variantType`` is implicit ``BND``, 
+          but it can also be set in an explicit manner using both ``mateName`` and
+          ``variantType=BND`` in a query.
+
 .. code-block:: javascript
 
     {