diff --git a/Dockerfile.phptest b/Dockerfile.phptest
index be2fb11..3c3e63a 100644
--- a/Dockerfile.phptest
+++ b/Dockerfile.phptest
@@ -3,5 +3,5 @@
 
 FROM registry.leenooks.net/leenooks/php:7.4-fpm-mp
 
-RUN apt-get pecl install xdebug \
+RUN pecl install xdebug \
 	&& docker-php-ext-enable xdebug