diff --git a/schema/refs/effect.schema.json b/schema/refs/effect.schema.json
index 1091734e5..e8f3fae21 100644
--- a/schema/refs/effect.schema.json
+++ b/schema/refs/effect.schema.json
@@ -774,6 +774,9 @@
         },
         "min": {
           "type": "number"
+        },
+        "alternate": {
+          "type": "boolean"
         }
       },
       "required": [