diff --git a/pkg/codegen/schema/pulumi.json b/pkg/codegen/schema/pulumi.json
index 4c6a6b270054..b5b93317f428 100644
--- a/pkg/codegen/schema/pulumi.json
+++ b/pkg/codegen/schema/pulumi.json
@@ -68,6 +68,7 @@
                     "format": "regex"
                 }
             },
+            "additionalProperties": false,
             "required": ["moduleFormat"]
         },
         "config": {
@@ -88,7 +89,8 @@
                         "type": "string"
                     }
                 }
-            }
+            },
+            "additionalProperties": false
         },
         "types": {
             "description": "A map from type token to complexTypeSpec that describes the set of complex types (i.e. object, enum) defined by this package.",
@@ -314,6 +316,7 @@
                             "type": "object"
                         }
                     },
+                    "additionalProperties": false,
                     "required": ["environment"]
                 },
                 "deprecationMessage": {