diff --git a/dev-scripts/run_tests.bat b/dev-scripts/run_tests.bat
index 14bb557..2eb0136 100644
--- a/dev-scripts/run_tests.bat
+++ b/dev-scripts/run_tests.bat
@@ -12,6 +12,7 @@ set "script_dir=%~dp0"
 set "work_dir=%script_dir%/.."
 cd %work_dir%
 
+call %PHP_BINARY% -c php-win.ini %composer_dir% update
 call %PHP_BINARY% -c php-win.ini vendor/bin/phpunit tests --debug
 
 endlocal