diff --git a/doc/build.md b/doc/build.md
index a1f04f28..dc207ffc 100644
--- a/doc/build.md
+++ b/doc/build.md
@@ -99,6 +99,8 @@ Babashka supports the following feature flags:
 | `BABASHKA_FEATURE_HTTPKIT_SERVER` | Includes the [http-kit](https://github.com/http-kit/http-kit) server library | `true` |
 | `BABASHKA_FEATURE_CORE_MATCH` | Includes the [clojure.core.match](https://github.com/clojure/core.match) library | `true` |
 | `BABASHKA_FEATURE_HICCUP` | Includes the [hiccup](https://github.com/weavejester/hiccup) library | `true` |
+| `BABASHKA_FEATURE_TEST_CHECK` | Includes the [clojure.test.check](https://github.com/clojure/test.check) library | `true` |
+| `BABASHKA_FEATURE_SPEC_ALPHA` | Includes the [clojure.spec.alpha](https://github.com/clojure/spec.alpha) library (WIP) | `false` |
 | `BABASHKA_FEATURE_JDBC` | Includes the [next.jdbc](https://github.com/seancorfield/next-jdbc) library | `false`    |
 | `BABASHKA_FEATURE_POSTGRESQL` | Includes the [PostgresSQL](https://jdbc.postgresql.org/) JDBC driver |  `false` |
 | `BABASHKA_FEATURE_HSQLDB` | Includes the [HSQLDB](http://www.hsqldb.org/) JDBC driver | `false` |