diff --git a/Dockerfile-debian.template b/Dockerfile-debian.template
index 161b5e71a4..edd9dd688b 100644
--- a/Dockerfile-debian.template
+++ b/Dockerfile-debian.template
@@ -2,17 +2,31 @@ FROM php:%%PHP_VERSION%%-%%VARIANT%%
 
 # install the PHP extensions we need
 RUN set -ex; \
+	\
+	savedAptMark="$(apt-mark showmanual)"; \
 	\
 	apt-get update; \
-	apt-get install -y \
+	apt-get install -y --no-install-recommends \
 		libjpeg-dev \
 		libpng-dev \
 	; \
-	rm -rf /var/lib/apt/lists/*; \
 	\
 	docker-php-ext-configure gd --with-png-dir=/usr --with-jpeg-dir=/usr; \
-	docker-php-ext-install gd mysqli opcache
-# TODO consider removing the *-dev deps and only keeping the necessary lib* packages
+	docker-php-ext-install gd mysqli opcache; \
+	\
+# reset apt-mark's "manual" list so that "purge --auto-remove" will remove all build dependencies
+	apt-mark auto '.*' > /dev/null; \
+	apt-mark manual $savedAptMark; \
+	ldd "$(php -r 'echo ini_get("extension_dir");')"/*.so \
+		| awk '/=>/ { print $3 }' \
+		| sort -u \
+		| xargs -r dpkg-query -S \
+		| cut -d: -f1 \
+		| sort -u \
+		| xargs -rt apt-mark manual; \
+	\
+	apt-get purge -y --auto-remove -o APT::AutoRemove::RecommendsImportant=false; \
+	rm -rf /var/lib/apt/lists/*
 
 # set recommended PHP.ini settings
 # see https://secure.php.net/manual/en/opcache.installation.php
diff --git a/php5.6/apache/Dockerfile b/php5.6/apache/Dockerfile
index 5abb3fd489..5ff9e011c2 100644
--- a/php5.6/apache/Dockerfile
+++ b/php5.6/apache/Dockerfile
@@ -2,17 +2,31 @@ FROM php:5.6-apache
 
 # install the PHP extensions we need
 RUN set -ex; \
+	\
+	savedAptMark="$(apt-mark showmanual)"; \
 	\
 	apt-get update; \
-	apt-get install -y \
+	apt-get install -y --no-install-recommends \
 		libjpeg-dev \
 		libpng-dev \
 	; \
-	rm -rf /var/lib/apt/lists/*; \
 	\
 	docker-php-ext-configure gd --with-png-dir=/usr --with-jpeg-dir=/usr; \
-	docker-php-ext-install gd mysqli opcache
-# TODO consider removing the *-dev deps and only keeping the necessary lib* packages
+	docker-php-ext-install gd mysqli opcache; \
+	\
+# reset apt-mark's "manual" list so that "purge --auto-remove" will remove all build dependencies
+	apt-mark auto '.*' > /dev/null; \
+	apt-mark manual $savedAptMark; \
+	ldd "$(php -r 'echo ini_get("extension_dir");')"/*.so \
+		| awk '/=>/ { print $3 }' \
+		| sort -u \
+		| xargs -r dpkg-query -S \
+		| cut -d: -f1 \
+		| sort -u \
+		| xargs -rt apt-mark manual; \
+	\
+	apt-get purge -y --auto-remove -o APT::AutoRemove::RecommendsImportant=false; \
+	rm -rf /var/lib/apt/lists/*
 
 # set recommended PHP.ini settings
 # see https://secure.php.net/manual/en/opcache.installation.php
diff --git a/php5.6/fpm/Dockerfile b/php5.6/fpm/Dockerfile
index 0f4e89c351..182b1cc7c4 100644
--- a/php5.6/fpm/Dockerfile
+++ b/php5.6/fpm/Dockerfile
@@ -2,17 +2,31 @@ FROM php:5.6-fpm
 
 # install the PHP extensions we need
 RUN set -ex; \
+	\
+	savedAptMark="$(apt-mark showmanual)"; \
 	\
 	apt-get update; \
-	apt-get install -y \
+	apt-get install -y --no-install-recommends \
 		libjpeg-dev \
 		libpng-dev \
 	; \
-	rm -rf /var/lib/apt/lists/*; \
 	\
 	docker-php-ext-configure gd --with-png-dir=/usr --with-jpeg-dir=/usr; \
-	docker-php-ext-install gd mysqli opcache
-# TODO consider removing the *-dev deps and only keeping the necessary lib* packages
+	docker-php-ext-install gd mysqli opcache; \
+	\
+# reset apt-mark's "manual" list so that "purge --auto-remove" will remove all build dependencies
+	apt-mark auto '.*' > /dev/null; \
+	apt-mark manual $savedAptMark; \
+	ldd "$(php -r 'echo ini_get("extension_dir");')"/*.so \
+		| awk '/=>/ { print $3 }' \
+		| sort -u \
+		| xargs -r dpkg-query -S \
+		| cut -d: -f1 \
+		| sort -u \
+		| xargs -rt apt-mark manual; \
+	\
+	apt-get purge -y --auto-remove -o APT::AutoRemove::RecommendsImportant=false; \
+	rm -rf /var/lib/apt/lists/*
 
 # set recommended PHP.ini settings
 # see https://secure.php.net/manual/en/opcache.installation.php
diff --git a/php7.0/apache/Dockerfile b/php7.0/apache/Dockerfile
index 13f3624949..5dffd476ee 100644
--- a/php7.0/apache/Dockerfile
+++ b/php7.0/apache/Dockerfile
@@ -2,17 +2,31 @@ FROM php:7.0-apache
 
 # install the PHP extensions we need
 RUN set -ex; \
+	\
+	savedAptMark="$(apt-mark showmanual)"; \
 	\
 	apt-get update; \
-	apt-get install -y \
+	apt-get install -y --no-install-recommends \
 		libjpeg-dev \
 		libpng-dev \
 	; \
-	rm -rf /var/lib/apt/lists/*; \
 	\
 	docker-php-ext-configure gd --with-png-dir=/usr --with-jpeg-dir=/usr; \
-	docker-php-ext-install gd mysqli opcache
-# TODO consider removing the *-dev deps and only keeping the necessary lib* packages
+	docker-php-ext-install gd mysqli opcache; \
+	\
+# reset apt-mark's "manual" list so that "purge --auto-remove" will remove all build dependencies
+	apt-mark auto '.*' > /dev/null; \
+	apt-mark manual $savedAptMark; \
+	ldd "$(php -r 'echo ini_get("extension_dir");')"/*.so \
+		| awk '/=>/ { print $3 }' \
+		| sort -u \
+		| xargs -r dpkg-query -S \
+		| cut -d: -f1 \
+		| sort -u \
+		| xargs -rt apt-mark manual; \
+	\
+	apt-get purge -y --auto-remove -o APT::AutoRemove::RecommendsImportant=false; \
+	rm -rf /var/lib/apt/lists/*
 
 # set recommended PHP.ini settings
 # see https://secure.php.net/manual/en/opcache.installation.php
diff --git a/php7.0/fpm/Dockerfile b/php7.0/fpm/Dockerfile
index 5001e76b39..eabe7e1369 100644
--- a/php7.0/fpm/Dockerfile
+++ b/php7.0/fpm/Dockerfile
@@ -2,17 +2,31 @@ FROM php:7.0-fpm
 
 # install the PHP extensions we need
 RUN set -ex; \
+	\
+	savedAptMark="$(apt-mark showmanual)"; \
 	\
 	apt-get update; \
-	apt-get install -y \
+	apt-get install -y --no-install-recommends \
 		libjpeg-dev \
 		libpng-dev \
 	; \
-	rm -rf /var/lib/apt/lists/*; \
 	\
 	docker-php-ext-configure gd --with-png-dir=/usr --with-jpeg-dir=/usr; \
-	docker-php-ext-install gd mysqli opcache
-# TODO consider removing the *-dev deps and only keeping the necessary lib* packages
+	docker-php-ext-install gd mysqli opcache; \
+	\
+# reset apt-mark's "manual" list so that "purge --auto-remove" will remove all build dependencies
+	apt-mark auto '.*' > /dev/null; \
+	apt-mark manual $savedAptMark; \
+	ldd "$(php -r 'echo ini_get("extension_dir");')"/*.so \
+		| awk '/=>/ { print $3 }' \
+		| sort -u \
+		| xargs -r dpkg-query -S \
+		| cut -d: -f1 \
+		| sort -u \
+		| xargs -rt apt-mark manual; \
+	\
+	apt-get purge -y --auto-remove -o APT::AutoRemove::RecommendsImportant=false; \
+	rm -rf /var/lib/apt/lists/*
 
 # set recommended PHP.ini settings
 # see https://secure.php.net/manual/en/opcache.installation.php
diff --git a/php7.1/apache/Dockerfile b/php7.1/apache/Dockerfile
index dc2391561d..3a75f2f1af 100644
--- a/php7.1/apache/Dockerfile
+++ b/php7.1/apache/Dockerfile
@@ -2,17 +2,31 @@ FROM php:7.1-apache
 
 # install the PHP extensions we need
 RUN set -ex; \
+	\
+	savedAptMark="$(apt-mark showmanual)"; \
 	\
 	apt-get update; \
-	apt-get install -y \
+	apt-get install -y --no-install-recommends \
 		libjpeg-dev \
 		libpng-dev \
 	; \
-	rm -rf /var/lib/apt/lists/*; \
 	\
 	docker-php-ext-configure gd --with-png-dir=/usr --with-jpeg-dir=/usr; \
-	docker-php-ext-install gd mysqli opcache
-# TODO consider removing the *-dev deps and only keeping the necessary lib* packages
+	docker-php-ext-install gd mysqli opcache; \
+	\
+# reset apt-mark's "manual" list so that "purge --auto-remove" will remove all build dependencies
+	apt-mark auto '.*' > /dev/null; \
+	apt-mark manual $savedAptMark; \
+	ldd "$(php -r 'echo ini_get("extension_dir");')"/*.so \
+		| awk '/=>/ { print $3 }' \
+		| sort -u \
+		| xargs -r dpkg-query -S \
+		| cut -d: -f1 \
+		| sort -u \
+		| xargs -rt apt-mark manual; \
+	\
+	apt-get purge -y --auto-remove -o APT::AutoRemove::RecommendsImportant=false; \
+	rm -rf /var/lib/apt/lists/*
 
 # set recommended PHP.ini settings
 # see https://secure.php.net/manual/en/opcache.installation.php
diff --git a/php7.1/fpm/Dockerfile b/php7.1/fpm/Dockerfile
index 74f3d84c14..a9e2678fa1 100644
--- a/php7.1/fpm/Dockerfile
+++ b/php7.1/fpm/Dockerfile
@@ -2,17 +2,31 @@ FROM php:7.1-fpm
 
 # install the PHP extensions we need
 RUN set -ex; \
+	\
+	savedAptMark="$(apt-mark showmanual)"; \
 	\
 	apt-get update; \
-	apt-get install -y \
+	apt-get install -y --no-install-recommends \
 		libjpeg-dev \
 		libpng-dev \
 	; \
-	rm -rf /var/lib/apt/lists/*; \
 	\
 	docker-php-ext-configure gd --with-png-dir=/usr --with-jpeg-dir=/usr; \
-	docker-php-ext-install gd mysqli opcache
-# TODO consider removing the *-dev deps and only keeping the necessary lib* packages
+	docker-php-ext-install gd mysqli opcache; \
+	\
+# reset apt-mark's "manual" list so that "purge --auto-remove" will remove all build dependencies
+	apt-mark auto '.*' > /dev/null; \
+	apt-mark manual $savedAptMark; \
+	ldd "$(php -r 'echo ini_get("extension_dir");')"/*.so \
+		| awk '/=>/ { print $3 }' \
+		| sort -u \
+		| xargs -r dpkg-query -S \
+		| cut -d: -f1 \
+		| sort -u \
+		| xargs -rt apt-mark manual; \
+	\
+	apt-get purge -y --auto-remove -o APT::AutoRemove::RecommendsImportant=false; \
+	rm -rf /var/lib/apt/lists/*
 
 # set recommended PHP.ini settings
 # see https://secure.php.net/manual/en/opcache.installation.php
diff --git a/php7.2/apache/Dockerfile b/php7.2/apache/Dockerfile
index 6c9b08927b..904b897f48 100644
--- a/php7.2/apache/Dockerfile
+++ b/php7.2/apache/Dockerfile
@@ -2,17 +2,31 @@ FROM php:7.2-apache
 
 # install the PHP extensions we need
 RUN set -ex; \
+	\
+	savedAptMark="$(apt-mark showmanual)"; \
 	\
 	apt-get update; \
-	apt-get install -y \
+	apt-get install -y --no-install-recommends \
 		libjpeg-dev \
 		libpng-dev \
 	; \
-	rm -rf /var/lib/apt/lists/*; \
 	\
 	docker-php-ext-configure gd --with-png-dir=/usr --with-jpeg-dir=/usr; \
-	docker-php-ext-install gd mysqli opcache
-# TODO consider removing the *-dev deps and only keeping the necessary lib* packages
+	docker-php-ext-install gd mysqli opcache; \
+	\
+# reset apt-mark's "manual" list so that "purge --auto-remove" will remove all build dependencies
+	apt-mark auto '.*' > /dev/null; \
+	apt-mark manual $savedAptMark; \
+	ldd "$(php -r 'echo ini_get("extension_dir");')"/*.so \
+		| awk '/=>/ { print $3 }' \
+		| sort -u \
+		| xargs -r dpkg-query -S \
+		| cut -d: -f1 \
+		| sort -u \
+		| xargs -rt apt-mark manual; \
+	\
+	apt-get purge -y --auto-remove -o APT::AutoRemove::RecommendsImportant=false; \
+	rm -rf /var/lib/apt/lists/*
 
 # set recommended PHP.ini settings
 # see https://secure.php.net/manual/en/opcache.installation.php
diff --git a/php7.2/fpm/Dockerfile b/php7.2/fpm/Dockerfile
index 1115254306..89d27e020c 100644
--- a/php7.2/fpm/Dockerfile
+++ b/php7.2/fpm/Dockerfile
@@ -2,17 +2,31 @@ FROM php:7.2-fpm
 
 # install the PHP extensions we need
 RUN set -ex; \
+	\
+	savedAptMark="$(apt-mark showmanual)"; \
 	\
 	apt-get update; \
-	apt-get install -y \
+	apt-get install -y --no-install-recommends \
 		libjpeg-dev \
 		libpng-dev \
 	; \
-	rm -rf /var/lib/apt/lists/*; \
 	\
 	docker-php-ext-configure gd --with-png-dir=/usr --with-jpeg-dir=/usr; \
-	docker-php-ext-install gd mysqli opcache
-# TODO consider removing the *-dev deps and only keeping the necessary lib* packages
+	docker-php-ext-install gd mysqli opcache; \
+	\
+# reset apt-mark's "manual" list so that "purge --auto-remove" will remove all build dependencies
+	apt-mark auto '.*' > /dev/null; \
+	apt-mark manual $savedAptMark; \
+	ldd "$(php -r 'echo ini_get("extension_dir");')"/*.so \
+		| awk '/=>/ { print $3 }' \
+		| sort -u \
+		| xargs -r dpkg-query -S \
+		| cut -d: -f1 \
+		| sort -u \
+		| xargs -rt apt-mark manual; \
+	\
+	apt-get purge -y --auto-remove -o APT::AutoRemove::RecommendsImportant=false; \
+	rm -rf /var/lib/apt/lists/*
 
 # set recommended PHP.ini settings
 # see https://secure.php.net/manual/en/opcache.installation.php