diff --git a/README.md b/README.md
index 54f97de..fe20ec9 100644
--- a/README.md
+++ b/README.md
@@ -21,7 +21,7 @@ What things you need to install and how to install them. These instructions are
 
 Install some ubuntu packages
 ```
-sudo apt-get install libpq-dev postgresql-12 postgresql-client-common postgresql-client libevent-dev apache2 php libapache2-mod-php php-pgsql libmagickwand-dev imagemagick php-imagick inkscape
+sudo apt-get install libpq-dev postgresql-12 postgresql-client-common postgresql-client libevent-dev apache2 php libapache2-mod-php php-dom php-pgsql libmagickwand-dev imagemagick php-imagick inkscape
 ```
 
 #### Install python