diff --git a/engine-contract.json b/engine-contract.json
index 27de973..6ce25ae 100644
--- a/engine-contract.json
+++ b/engine-contract.json
@@ -248,6 +248,13 @@
         "internal/ir/docplan/compiler.go"
       ]
     },
+    {
+      "name": "DocumentQueries::Differ",
+      "kind": "document",
+      "consumers": [
+        "internal/ir/queryplan/compiler.go"
+      ]
+    },
     {
       "name": "DocumentQueries::Distinct",
       "kind": "document",