diff --git a/docs/php_modules.md b/docs/php_modules.md
index 843d6b6..976ac08 100644
--- a/docs/php_modules.md
+++ b/docs/php_modules.md
@@ -14,3 +14,21 @@ supervisorctl restart php-fpm
 ```
 
 We may include a env var to do this in the future.
+
+## Extensions already installed
+The following are already installed and ready to use:
+
+| `docker-php-ext-`name | Description 
+|----|----|
+| curl | cURL: command line tool and library for transferring data with URLs
+| dom | **DOM**-manipulation library 
+| gd | **GD**: Image creation and manipulation library 
+| intl | **Internationalization** (i18n) function library 
+| mysqli | **MySQL Improved**: Procedural-style  library for connecting to and using a MySQL database
+| opcache | **OPcache**: Improves PHP performace by storing precompiled script bytecode in shared memory 
+| pdo | **PDO**: PHP Database Object; Object-oriented library for connecting to various databases.
+| pdo_mysql | **MySQL Driver** for PDO
+| pdo_sqlite | **SQLite Driver** for PDO
+| soap | **SOAP**: **S**imple **O**bject **A**ccess **P**rotocol library
+| xsl | **XSL**: e**X**stensible **S**tyling **L**anguage library
+| zip | **ZIP**: Transparently read and write ZIP compressed archives