diff --git a/scripts/docker_install.sh b/scripts/docker_install.sh
index bff09e7e6d2edca9b9aba87788378457b291ad9d..a758fdc6266c3063713ba959c9a8190a553b2dbd 100644
--- a/scripts/docker_install.sh
+++ b/scripts/docker_install.sh
@@ -23,7 +23,7 @@ apt-get install libfreetype6-dev \
 # required php extensions not included in base php image
 pecl install imagick-3.4.3RC1
 docker-php-ext-enable imagick
-docker-php-ext-install mysqli mcrypt gettext
+docker-php-ext-install mysqli mcrypt gettext calendar
 docker-php-ext-configure gd --with-freetype-dir=/usr/include/ --with-jpeg-dir=/usr/include/
 docker-php-ext-install gd