diff --git a/docs/api/js-yaml-schema.createinclude.md b/docs/api/js-yaml-schema.createinclude.md
index 27959a0..0dc67c0 100644
--- a/docs/api/js-yaml-schema.createinclude.md
+++ b/docs/api/js-yaml-schema.createinclude.md
@@ -9,16 +9,19 @@ Instantiate an includer with closure over the provided options.
 <b>Signature:</b>
 
 ```typescript
-export declare function createInclude(options: IncludeOptions): YamlType;
+export declare function createInclude(options: Readonly<IncludeOptions>): {
+    includeType: YamlType;
+    setSchema: (schema: Schema) => void;
+};
 ```
 
 ## Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  options | [IncludeOptions](./js-yaml-schema.includeoptions.md) |  |
+|  options | Readonly&lt;[IncludeOptions](./js-yaml-schema.includeoptions.md)<!-- -->&gt; |  |
 
 <b>Returns:</b>
 
-YamlType
+{ includeType: YamlType; setSchema: (schema: Schema) =&gt; void; }
 
diff --git a/docs/api/js-yaml-schema.createschema.md b/docs/api/js-yaml-schema.createschema.md
index df6b5af..9c55ec7 100644
--- a/docs/api/js-yaml-schema.createschema.md
+++ b/docs/api/js-yaml-schema.createschema.md
@@ -9,16 +9,16 @@ Safe schema with additional library types added.
 <b>Signature:</b>
 
 ```typescript
-export declare function createSchema(options: SchemaOptions): Schema;
+export declare function createSchema(options: Readonly<SchemaOptions>): import("js-yaml").Schema;
 ```
 
 ## Parameters
 
 |  Parameter | Type | Description |
 |  --- | --- | --- |
-|  options | [SchemaOptions](./js-yaml-schema.schemaoptions.md) |  |
+|  options | Readonly&lt;[SchemaOptions](./js-yaml-schema.schemaoptions.md)<!-- -->&gt; |  |
 
 <b>Returns:</b>
 
-Schema
+import("js-yaml").Schema
 
diff --git a/docs/api/js-yaml-schema.includeoptions.md b/docs/api/js-yaml-schema.includeoptions.md
index 7ae75fb..275c2c2 100644
--- a/docs/api/js-yaml-schema.includeoptions.md
+++ b/docs/api/js-yaml-schema.includeoptions.md
@@ -18,5 +18,5 @@ export interface IncludeOptions
 |  [join](./js-yaml-schema.includeoptions.join.md) | (...path: Array&lt;string&gt;) =&gt; string |  |
 |  [read](./js-yaml-schema.includeoptions.read.md) | IncludeReader |  |
 |  [resolve](./js-yaml-schema.includeoptions.resolve.md) | (path: string) =&gt; string |  |
-|  [schema](./js-yaml-schema.includeoptions.schema.md) | Schema |  |
+|  [schema](./js-yaml-schema.includeoptions.schema.md) | Optional&lt;Schema&gt; |  |
 
diff --git a/docs/api/js-yaml-schema.includeoptions.schema.md b/docs/api/js-yaml-schema.includeoptions.schema.md
index f05f3d1..9c44cb0 100644
--- a/docs/api/js-yaml-schema.includeoptions.schema.md
+++ b/docs/api/js-yaml-schema.includeoptions.schema.md
@@ -7,5 +7,5 @@
 <b>Signature:</b>
 
 ```typescript
-schema: Schema;
+schema: Optional<Schema>;
 ```
diff --git a/docs/api/js-yaml-schema.schemaoptions.include.md b/docs/api/js-yaml-schema.schemaoptions.include.md
index ff5507d..6ea564b 100644
--- a/docs/api/js-yaml-schema.schemaoptions.include.md
+++ b/docs/api/js-yaml-schema.schemaoptions.include.md
@@ -7,5 +7,5 @@
 <b>Signature:</b>
 
 ```typescript
-include: IncludeOptions;
+include: Readonly<IncludeOptions>;
 ```
diff --git a/docs/api/js-yaml-schema.schemaoptions.md b/docs/api/js-yaml-schema.schemaoptions.md
index 8901772..52c29b3 100644
--- a/docs/api/js-yaml-schema.schemaoptions.md
+++ b/docs/api/js-yaml-schema.schemaoptions.md
@@ -14,5 +14,5 @@ export interface SchemaOptions
 
 |  Property | Type | Description |
 |  --- | --- | --- |
-|  [include](./js-yaml-schema.schemaoptions.include.md) | [IncludeOptions](./js-yaml-schema.includeoptions.md) |  |
+|  [include](./js-yaml-schema.schemaoptions.include.md) | Readonly&lt;[IncludeOptions](./js-yaml-schema.includeoptions.md)<!-- -->&gt; |  |
 
diff --git a/package.json b/package.json
index e8158d8..9d8b25f 100644
--- a/package.json
+++ b/package.json
@@ -14,7 +14,7 @@
     "@apextoaster/js-utils": "0.2.1",
     "@istanbuljs/nyc-config-typescript": "1.0.1",
     "@microsoft/api-documenter": "7.12.14",
-    "@microsoft/api-extractor": "7.13.2",
+    "@microsoft/api-extractor": "7.13.2-pr1916.0",
     "@types/chai": "4.2.15",
     "@types/chai-as-promised": "7.1.3",
     "@types/js-yaml": "4.0.0",
diff --git a/yarn.lock b/yarn.lock
index 7f8dc81..11afcf1 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -213,7 +213,7 @@
     js-yaml "~3.13.1"
     resolve "~1.17.0"
 
-"@microsoft/api-extractor-model@7.12.2":
+"@microsoft/api-extractor-model@7.12.2", "@microsoft/api-extractor-model@workspace:*":
   version "7.12.2"
   resolved "https://artifacts.apextoaster.com/repository/group-npm/@microsoft/api-extractor-model/-/api-extractor-model-7.12.2.tgz#d48b35e8ed20643b1c19d7a4f80c90c42dc7d1d8"
   integrity sha512-EU+U09Mj65zUH0qwPF4PFJiL6Y+PQQE/RRGEHEDGJJzab/mRQDpKOyrzSdb00xvcd/URehIHJqC55cY2Y4jGOA==
@@ -221,16 +221,16 @@
     "@microsoft/tsdoc" "0.12.24"
     "@rushstack/node-core-library" "3.36.0"
 
-"@microsoft/api-extractor@7.13.2":
-  version "7.13.2"
-  resolved "https://artifacts.apextoaster.com/repository/group-npm/@microsoft/api-extractor/-/api-extractor-7.13.2.tgz#c44762d27aee05c4da16c03fc8786bd0fa31c7eb"
-  integrity sha512-2fD0c8OxZW+e6NTaxbtrdNxXVuX7aqil3+cqig3pKsHymvUuRJVCEAcAJmZrJ/ENqYXNiB265EyqOT6VxbMysw==
+"@microsoft/api-extractor@7.13.2-pr1916.0":
+  version "7.13.2-pr1916.0"
+  resolved "https://artifacts.apextoaster.com/repository/group-npm/@microsoft/api-extractor/-/api-extractor-7.13.2-pr1916.0.tgz#2e10cb928ea81b56cd5f63264da11f1f9b9310a5"
+  integrity sha512-0/HajL+NUixuNGMfFZbHmKJn5VEqiF45q2FXhu8UrggutdJ+9M6wZ++fejUHfxlC/WhQVrVVRtf4xvVM3oIW+A==
   dependencies:
-    "@microsoft/api-extractor-model" "7.12.2"
+    "@microsoft/api-extractor-model" "workspace:*"
     "@microsoft/tsdoc" "0.12.24"
-    "@rushstack/node-core-library" "3.36.0"
-    "@rushstack/rig-package" "0.2.10"
-    "@rushstack/ts-command-line" "4.7.8"
+    "@rushstack/node-core-library" "workspace:*"
+    "@rushstack/rig-package" "workspace:*"
+    "@rushstack/ts-command-line" "workspace:*"
     colors "~1.2.1"
     lodash "~4.17.15"
     resolve "~1.17.0"
@@ -279,7 +279,7 @@
     estree-walker "^2.0.1"
     picomatch "^2.2.2"
 
-"@rushstack/node-core-library@3.36.0":
+"@rushstack/node-core-library@3.36.0", "@rushstack/node-core-library@workspace:*":
   version "3.36.0"
   resolved "https://artifacts.apextoaster.com/repository/group-npm/@rushstack/node-core-library/-/node-core-library-3.36.0.tgz#95dace39d763c8695d6607c421f95c6ac65b0ed4"
   integrity sha512-bID2vzXpg8zweXdXgQkKToEdZwVrVCN9vE9viTRk58gqzYaTlz4fMId6V3ZfpXN6H0d319uGi2KDlm+lUEeqCg==
@@ -294,7 +294,7 @@
     timsort "~0.3.0"
     z-schema "~3.18.3"
 
-"@rushstack/rig-package@0.2.10":
+"@rushstack/rig-package@workspace:*":
   version "0.2.10"
   resolved "https://artifacts.apextoaster.com/repository/group-npm/@rushstack/rig-package/-/rig-package-0.2.10.tgz#e861eb94953d8c22c509dc3e9d91d6f337eab3cd"
   integrity sha512-WXYerEJEPf8bS3ruqfM57NnwXtA7ehn8VJjLjrjls6eSduE5CRydcob/oBTzlHKsQ7N196XKlqQl9P6qIyYG2A==
@@ -302,7 +302,7 @@
     resolve "~1.17.0"
     strip-json-comments "~3.1.1"
 
-"@rushstack/ts-command-line@4.7.8":
+"@rushstack/ts-command-line@4.7.8", "@rushstack/ts-command-line@workspace:*":
   version "4.7.8"
   resolved "https://artifacts.apextoaster.com/repository/group-npm/@rushstack/ts-command-line/-/ts-command-line-4.7.8.tgz#3aa77cf544c571be3206fc2bcba20c7a096ed254"
   integrity sha512-8ghIWhkph7NnLCMDJtthpsb7TMOsVGXVDvmxjE/CeklTqjbbUFBjGXizJfpbEkRQTELuZQ2+vGn7sGwIWKN2uA==