diff --git a/source/behavior/entities/format/components/interact.json b/source/behavior/entities/format/components/interact.json
index bb1249eb..dd1add77 100644
--- a/source/behavior/entities/format/components/interact.json
+++ b/source/behavior/entities/format/components/interact.json
@@ -8,6 +8,7 @@
   "definitions": {
     "interaction_spec": {
       "type": "object",
+      "additionalProperties": false,
       "properties": {
         "add_items": {
           "type": "object",