diff --git a/docker/Dockerfile b/docker/Dockerfile
index f519cf1..d7b8cb4 100644
--- a/docker/Dockerfile
+++ b/docker/Dockerfile
@@ -9,9 +9,18 @@ RUN if [ -n ${HTTP_PROXY} ] ; then sed -i -e s'/https/http/' /etc/apk/repositori
 # Base
 RUN apk add --no-cache bash msmtp memcached
 
+ENV SITE_USER=www-data
+
 # Additional extensions:
 RUN install-php-extensions \
-    igbinary msgpack memcached zip bz2 zstd brotli gd intl
+    opcache igbinary msgpack memcached zip bz2 zstd brotli gd intl \
+    && echo opcache.memory_consumption=512 >> /usr/local/etc/php/conf.d/docker-php-ext-opcache.ini \
+    && echo opcache.interned_strings_buffer=64 >> /usr/local/etc/php/conf.d/docker-php-ext-opcache.ini \
+    && echo opcache.max_accelerated_files=32531 >> /usr/local/etc/php/conf.d/docker-php-ext-opcache.ini \
+    && echo opcache.fast_shutdown=1 >> /usr/local/etc/php/conf.d/docker-php-ext-opcache.ini \
+    && echo opcache.enable_cli=1 >> /usr/local/etc/php/conf.d/docker-php-ext-opcache.ini \
+    && mkdir /tmp/opcache && chown ${SITE_USER}:0 /tmp/opcache && chmod 750 /tmp/opcache && echo opcache.file_cache=/tmp/opcache >> /usr/local/etc/php/conf.d/docker-php-ext-opcache.ini \
+    && echo opcache.validate_timestamps=0 >> /usr/local/etc/php/conf.d/docker-php-ext-opcache.ini
 
 # Tune PHP
 RUN cp /usr/local/etc/php/php.ini-production /usr/local/etc/php/php.ini
@@ -26,8 +35,6 @@ COPY wait-for-it /usr/local/bin/
 RUN curl -4 https://getcomposer.org/installer|php -- --install-dir=/usr/local/bin --filename=composer
 ENV COMPOSER_HOME=/var/cache/composer
 
-ENV SITE_USER=www-data
-
 # Other config
 COPY msmtprc /etc/