diff --git a/CHANGELOG.md b/CHANGELOG.md
index 668d43f5..48cf6b3a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -31,6 +31,10 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Clarified that gsd should only be used on an asset to represent the sensor, not just different processing. ([#1105](https://github.com/radiantearth/stac-spec/pull/1105))
 - Clarified that leaving a field out is not equivalent to setting it as null. ([#1111](https://github.com/radiantearth/stac-spec/pull/1111))
 
+### Fixed
+
+- JSON Schemas don't allow "shortcuts" for core extensions any longer
+
 ## [v1.0.0-rc.2] - 2021-03-30
 
 ### Changed
diff --git a/catalog-spec/json-schema/catalog-core.json b/catalog-spec/json-schema/catalog-core.json
index 987fe547..fece50e3 100644
--- a/catalog-spec/json-schema/catalog-core.json
+++ b/catalog-spec/json-schema/catalog-core.json
@@ -29,17 +29,9 @@
           "type": "array",
           "uniqueItems": true,
           "items": {
-            "anyOf": [
-              {
-                "title": "Reference to a JSON Schema",
-                "type": "string",
-                "format": "iri"
-              },
-              {
-                "title": "Reference to a core extension",
-                "type": "string"
-              }
-            ]
+            "title": "Reference to a JSON Schema",
+            "type": "string",
+            "format": "iri"
           }
         },
         "id": {
diff --git a/collection-spec/json-schema/collection.json b/collection-spec/json-schema/collection.json
index 942144c1..1d2fc11d 100644
--- a/collection-spec/json-schema/collection.json
+++ b/collection-spec/json-schema/collection.json
@@ -31,17 +31,9 @@
           "type": "array",
           "uniqueItems": true,
           "items": {
-            "anyOf": [
-              {
-                "title": "Reference to a JSON Schema",
-                "type": "string",
-                "format": "iri"
-              },
-              {
-                "title": "Reference to a core extension",
-                "type": "string"
-              }
-            ]
+            "title": "Reference to a JSON Schema",
+            "type": "string",
+            "format": "iri"
           }
         },
         "keywords": {
diff --git a/item-spec/json-schema/item.json b/item-spec/json-schema/item.json
index 10bfa2b2..87d0b14d 100644
--- a/item-spec/json-schema/item.json
+++ b/item-spec/json-schema/item.json
@@ -100,17 +100,9 @@
               "type": "array",
               "uniqueItems": true,
               "items": {
-                "anyOf": [
-                  {
-                    "title": "Reference to a JSON Schema",
-                    "type": "string",
-                    "format": "iri"
-                  },
-                  {
-                    "title": "Reference to a core extension",
-                    "type": "string"
-                  }
-                ]
+                "title": "Reference to a JSON Schema",
+                "type": "string",
+                "format": "iri"
               }
             },
             "id": {