diff --git a/README.md b/README.md
index 155bf02..677feb2 100644
--- a/README.md
+++ b/README.md
@@ -42,7 +42,7 @@ This Plugin provides:
 1. Read the [contributing guidelines][contributing];
 1. clone this repository (`git clone git@github.com:markcheret/footnotes.git`):
     - we recommend that you use [VVV][vvv] for your local testing environment.
-1. install [Composer][composer], if you don't have it already; and
+1. install [Composer][composer] and [NPM][npm]; and
 1. install all dependencies (`composer install`):
     - you will have to install `php-mbstring` manually if you do not already 
       have it.
@@ -149,6 +149,7 @@ This project is licensed under the [GNU GPL v3][gpl-v3].
 [contributing]: https://github.com/markcheret/footnotes/blob/main/CONTRIBUTING.md
 [vvv]: https://varyingvagrantvagrants.org/
 [composer]: https://getcomposer.org/download/
+[npm]: https://www.npmjs.com/
 [wpcs-php]: https://developer.wordpress.org/coding-standards/wordpress-coding-standards/php/
 [phpcs]: https://github.com/squizlabs/PHP_CodeSniffer
 [wpcs-js]: https://developer.wordpress.org/coding-standards/wordpress-coding-standards/javascript/
diff --git a/composer.json b/composer.json
index b8374a9..7a919f3 100644
--- a/composer.json
+++ b/composer.json
@@ -20,7 +20,7 @@
         "format:js:fix": "npm run format:js:fix",
         "docs": "./vendor/bin/phpdoc -d . -t ./docs --ignore vendor/",
         "commit": "./vendor/bin/php-commitizen commit -- ./.php-commitizen.php",
-        "post-install-cmd": "./_tools/setup.sh"
+        "post-install-cmd": "npm install && ./_tools/setup.sh"
     },
     "require-dev": {
         "dealerdirect/phpcodesniffer-composer-installer": "^0.7.1",
diff --git a/composer.lock b/composer.lock
index 79b7024..35d5665 100644
--- a/composer.lock
+++ b/composer.lock
@@ -1400,19 +1400,20 @@
         },
         {
             "name": "marcocesarato/php-conventional-changelog",
-            "version": "v1.9.10",
+            "version": "1.10.1",
             "source": {
                 "type": "git",
                 "url": "https://github.com/marcocesarato/php-conventional-changelog.git",
-                "reference": "ecf53957bd84126f024f261c4b2fef4a889aafd2"
+                "reference": "c84d617e0081db7d390cab585facb703f0ea9536"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/marcocesarato/php-conventional-changelog/zipball/ecf53957bd84126f024f261c4b2fef4a889aafd2",
-                "reference": "ecf53957bd84126f024f261c4b2fef4a889aafd2",
+                "url": "https://api.github.com/repos/marcocesarato/php-conventional-changelog/zipball/c84d617e0081db7d390cab585facb703f0ea9536",
+                "reference": "c84d617e0081db7d390cab585facb703f0ea9536",
                 "shasum": ""
             },
             "require": {
+                "ext-json": "*",
                 "php": ">=7.1.3",
                 "symfony/console": "^4 || ^5"
             },
@@ -1467,9 +1468,9 @@
             ],
             "support": {
                 "issues": "https://github.com/marcocesarato/php-conventional-changelog/issues",
-                "source": "https://github.com/marcocesarato/php-conventional-changelog/tree/v1.9.10"
+                "source": "https://github.com/marcocesarato/php-conventional-changelog/tree/v1.10.1"
             },
-            "time": "2021-04-13T19:48:52+00:00"
+            "time": "2021-04-15T12:15:06+00:00"
         },
         {
             "name": "monolog/monolog",