diff --git a/.docker/php53/Dockerfile b/.docker/php53/Dockerfile
deleted file mode 100644
index 99ca06bf0..000000000
--- a/.docker/php53/Dockerfile
+++ /dev/null
@@ -1,57 +0,0 @@
-FROM buildpack-deps:jessie
-
-ENV PHP_VERSION 5.3.29
-
-# php 5.3 needs older autoconf
-RUN set -eux; \
-  \
-  apt-get update; \
-  apt-get install -y \
-    curl \
-    autoconf2.13 \
-  ; \
-  rm -r /var/lib/apt/lists/*; \
-  \
-  curl -sSLfO http://launchpadlibrarian.net/140087283/libbison-dev_2.7.1.dfsg-1_amd64.deb; \
-  curl -sSLfO http://launchpadlibrarian.net/140087282/bison_2.7.1.dfsg-1_amd64.deb; \
-  dpkg -i libbison-dev_2.7.1.dfsg-1_amd64.deb; \
-  dpkg -i bison_2.7.1.dfsg-1_amd64.deb; \
-  rm *.deb; \
-  \
-  curl -sSLf "https://php.net/get/php-$PHP_VERSION.tar.bz2/from/this/mirror" -o php.tar.bz2; \
-  echo 'c4e1cf6972b2a9c7f2777a18497d83bf713cdbecabb65d3ff62ba441aebb0091  php.tar.bz2' | sha256sum -cw --status; \
-  \
-  mkdir -p /usr/src/php; \
-  tar -xf php.tar.bz2 -C /usr/src/php --strip-components=1; \
-  rm php.tar.bz2*; \
-  \
-  cd /usr/src/php; \
-  ./buildconf --force; \
-  ./configure --disable-cgi \
-    $(command -v apxs2 > /dev/null 2>&1 && echo '--with-apxs2' || true) \
-    --with-pdo-mysql \
-    --with-zlib \
-    --enable-mbstring \
-  ; \
-  make -j"$(nproc)"; \
-  make install; \
-  \
-  dpkg -r \
-    bison \
-    libbison-dev \
-  ; \
-  apt-get purge -y --auto-remove \
-    autoconf2.13 \
-  ; \
-  rm -r /usr/src/php
-
-# Install APC PHP extension
-#
-RUN set -eux; \
-  \
-  pecl install apc-3.1.13; \
-  echo 'extension=apc.so' >> /usr/local/lib/php.ini; \
-  \
-  rm -r /tmp/pear;
-
-CMD ["php", "-a"]
diff --git a/.docker/php54/Dockerfile b/.docker/php54/Dockerfile
deleted file mode 100644
index ef5acfd0e..000000000
--- a/.docker/php54/Dockerfile
+++ /dev/null
@@ -1,34 +0,0 @@
-FROM php:5.4-cli
-
-RUN docker-php-ext-install pdo
-RUN docker-php-ext-install pdo_mysql
-RUN docker-php-ext-install mbstring
-
-# Install APC PHP extension
-#
-RUN set -eux; \
-  pecl install apc-3.1.13; \
-  docker-php-ext-enable apc; \
-  rm -r /tmp/pear;
-
-# Install memcache PHP extension
-#
-ARG MEMCACHE_VERSION
-RUN set -eux; \
-  buildDeps=' \
-    libzip-dev \
-  '; \
-  apt-get update; \
-  apt-get install -y --no-upgrade --no-install-recommends \
-    $buildDeps \
-  ; \
-  \
-  pecl install memcache-${MEMCACHE_VERSION}; \
-  docker-php-ext-enable memcache; \
-  \
-  apt-get purge -y --auto-remove -o APT::AutoRemove::RecommendsImportant=true \
-    $buildDeps \
-  ; \
-  apt-get clean; \
-  rm -rf /var/lib/apt/lists/*; \
-  rm -r /tmp/pear
diff --git a/.docker/php55_71/Dockerfile b/.docker/php55_71/Dockerfile
deleted file mode 100644
index 1aa2171a3..000000000
--- a/.docker/php55_71/Dockerfile
+++ /dev/null
@@ -1,40 +0,0 @@
-ARG PHP_TAG
-FROM php:${PHP_TAG}
-
-RUN docker-php-ext-install pdo
-RUN docker-php-ext-install pdo_mysql
-RUN docker-php-ext-install mbstring
-
-# Install APCu PHP extension
-#
-ARG APCU_VERSION
-RUN set -eux; \
-  \
-  test x"" = x"${APCU_VERSION}" || { \
-    pecl install apcu-${APCU_VERSION}; \
-    docker-php-ext-enable apcu; \
-    \
-    rm -r /tmp/pear; \
-  }
-
-# Install memcache PHP extension
-#
-ARG MEMCACHE_VERSION
-RUN set -eux; \
-  buildDeps=' \
-    libzip-dev \
-  '; \
-  apt-get update; \
-  apt-get install -y --no-upgrade --no-install-recommends \
-    $buildDeps \
-  ; \
-  \
-  pecl install memcache-${MEMCACHE_VERSION}; \
-  docker-php-ext-enable memcache; \
-  \
-  apt-get purge -y --auto-remove -o APT::AutoRemove::RecommendsImportant=true \
-    $buildDeps \
-  ; \
-  apt-get clean; \
-  rm -rf /var/lib/apt/lists/*; \
-  rm -r /tmp/pear
diff --git a/.docker/php72_73/Dockerfile b/.docker/php72_73/Dockerfile
deleted file mode 100644
index 69353468b..000000000
--- a/.docker/php72_73/Dockerfile
+++ /dev/null
@@ -1,56 +0,0 @@
-ARG PHP_VERSION
-FROM php:${PHP_VERSION}-cli
-
-RUN docker-php-ext-install pdo
-RUN docker-php-ext-install pdo_mysql
-RUN docker-php-ext-install mbstring
-
-# Install APCu PHP extension
-#
-ARG APCU_VERSION
-RUN set -eux; \
-  \
-  test x"" = x"${APCU_VERSION}" || { \
-    pecl install apcu-${APCU_VERSION}; \
-    docker-php-ext-enable apcu; \
-    \
-    rm -r /tmp/pear; \
-  }
-
-# Install memcache PHP extension
-#
-ARG MEMCACHE_VERSION
-RUN set -eux; \
-  buildDeps=' \
-    libzip-dev \
-  '; \
-  apt-get update; \
-  apt-get install -y --no-upgrade --no-install-recommends \
-    $buildDeps \
-  ; \
-  \
-  pecl install memcache-${MEMCACHE_VERSION}; \
-  docker-php-ext-enable memcache; \
-  \
-  apt-get purge -y --auto-remove -o APT::AutoRemove::RecommendsImportant=true \
-    $buildDeps \
-  ; \
-  apt-get clean; \
-  rm -rf /var/lib/apt/lists/*; \
-  rm -r /tmp/pear
-
-# For consistent mime type file guesser
-RUN set -eux; \
-  distFilePath=`which file`; \
-  \
-  mv ${distFilePath} ${distFilePath}.dist; \
-  { \
-    echo '#! /bin/sh -eu'; \
-    echo ''; \
-    echo "${distFilePath}"'.dist "$@" | sed -e s,application/x-pie-executable,application/x-executable,g'; \
-  } | tee ${distFilePath}; \
-  \
-  chmod +x ${distFilePath}; \
-  \
-  file /bin/ls --mime | grep application/x-executable; \
-  :;
diff --git a/.docker/php74_83/Dockerfile b/.docker/php82_83/Dockerfile
similarity index 100%
rename from .docker/php74_83/Dockerfile
rename to .docker/php82_83/Dockerfile
diff --git a/.github/workflows/continuous-integration.yml b/.github/workflows/continuous-integration.yml
index 47e723aed..4dbb595e3 100644
--- a/.github/workflows/continuous-integration.yml
+++ b/.github/workflows/continuous-integration.yml
@@ -17,9 +17,6 @@ jobs:
     strategy:
       matrix:
         php-version:
-          - "7.4"
-          - "8.0"
-          - "8.1"
           - "8.2"
           - "8.3"
         memcached-version:
diff --git a/composer.json b/composer.json
index a424d6ea6..b383f48a0 100755
--- a/composer.json
+++ b/composer.json
@@ -4,7 +4,7 @@
     "type": "library",
     "license": "MIT",
     "require": {
-        "php" : ">=5.3.0",
+        "php" : ">=8.2.0",
         "swiftmailer/swiftmailer": "~5.2 || ^6.0"
     },
     "require-dev": {
diff --git a/docker-compose.yml b/docker-compose.yml
index b0f11aa46..634943eb0 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -15,35 +15,13 @@ services:
       - |
         exec tail -f /dev/null
 
-  php53:
-    build: .docker/php53
-    working_dir: /app
-    volumes:
-      - .:/app
-      - db_socket:/var/run/mysqld
-    entrypoint:
-      - sh
-      - -c
-      - |
-        {
-          echo 'pdo_mysql.default_socket = /var/run/mysqld/mysql.sock'
-          echo 'memory_limit = -1'
-          echo 'short_open_tag = off'
-          echo 'magic_quotes_gpc = off'
-          echo 'date.timezone = "UTC"'
-          echo 'apc.enable_cli = on'
-          echo 'apc.use_request_time = 0'
-        } | tee -a /usr/local/lib/php.ini
-
-        exec tail -f /dev/null
-    depends_on:
-      - db
-
-  php54: &services_php54
+  php82: &services_php82
     build:
-      context: .docker/php54
+      context: .docker/php82_83
       args:
-        MEMCACHE_VERSION: '3.0.8'
+        PHP_VERSION: '8.2'
+        MEMCACHE_VERSION: '8.0'
+        APCU_VERSION: '5.1.23'
     environment:
       MEMCACHED_HOST: memcached
     working_dir: /app
@@ -69,105 +47,10 @@ services:
       - db
       - memcached
 
-  php55:
-    <<: *services_php54
-    build:
-      context: .docker/php55_71
-      args:
-        PHP_TAG: '5.5-cli'
-        MEMCACHE_VERSION: '3.0.8'
-        APCU_VERSION: '4.0.11'
-
-  php56:
-    <<: *services_php54
-    build:
-      context: .docker/php55_71
-      args:
-        PHP_TAG: '5.6-cli-jessie'
-        MEMCACHE_VERSION: '3.0.8'
-        APCU_VERSION: '4.0.11'
-
-  php70:
-    <<: *services_php54
-    build:
-      context: .docker/php55_71
-      args:
-        PHP_TAG: '7.0-cli-jessie'
-        MEMCACHE_VERSION: '4.0.5.2'
-        APCU_VERSION: '5.1.23'
-
-  php71:
-    <<: *services_php54
-    build:
-      context: .docker/php55_71
-      args:
-        PHP_TAG: '7.1-cli-jessie'
-        MEMCACHE_VERSION: '4.0.5.2'
-        APCU_VERSION: '5.1.23'
-
-
-  php72:
-    <<: *services_php54
-    build:
-      context: .docker/php72_73
-      args:
-        PHP_VERSION: '7.2'
-        MEMCACHE_VERSION: '4.0.5.2'
-        APCU_VERSION: '5.1.23'
-
-
-  php73:
-    <<: *services_php54
-    build:
-      context: .docker/php72_73
-      args:
-        PHP_VERSION: '7.3'
-        MEMCACHE_VERSION: '4.0.5.2'
-        APCU_VERSION: '5.1.23'
-
-
-  php74:
-    <<: *services_php54
-    build:
-      context: .docker/php74_83
-      args:
-        PHP_VERSION: '7.4'
-        MEMCACHE_VERSION: '4.0.5.2'
-        APCU_VERSION: '5.1.23'
-
-
-  php80:
-    <<: *services_php54
-    build:
-      context: .docker/php74_83
-      args:
-        PHP_VERSION: '8.0'
-        MEMCACHE_VERSION: '8.0'
-        APCU_VERSION: '5.1.23'
-
-
-  php81:
-    <<: *services_php54
-    build:
-      context: .docker/php74_83
-      args:
-        PHP_VERSION: '8.1'
-        MEMCACHE_VERSION: '8.0'
-        APCU_VERSION: '5.1.23'
-
-  php82:
-    <<: *services_php54
-    build:
-      context: .docker/php74_83
-      args:
-        PHP_VERSION: '8.2'
-        MEMCACHE_VERSION: '8.0'
-        APCU_VERSION: '5.1.23'
-
   php83:
-    <<: *services_php54
+    <<: *services_php82
     build:
-      context: .docker/php74_83
+      context: .docker/php82_83
       args:
         PHP_VERSION: '8.3'
         MEMCACHE_VERSION: '8.0'