diff --git a/Makefile b/Makefile
index f08e3765..4357317f 100644
--- a/Makefile
+++ b/Makefile
@@ -8,8 +8,11 @@ checks: test phpcs ## Everything CI runs before merging (needs `composer install
 test: ## Run the pure-PHP test suites
 	php tests/QuotesTest.php
 
-phpcs: ## parallel-lint + minus-x + phpcs against the MediaWiki coding standard
+phpcs: vendor/autoload.php ## parallel-lint + minus-x + phpcs against the MediaWiki coding standard
 	composer test
 
+vendor/autoload.php: composer.json
+	composer install --no-progress
+
 mathjax: ## Pin the local MathJax submodule + CDN major version, e.g. `make mathjax MATHJAX_VERSION_LOCAL=4.1.3 MATHJAX_VERSION_CDN=4`
 	hack/mathjax.sh $(MATHJAX_VERSION_LOCAL) $(MATHJAX_VERSION_CDN)