diff --git a/web-apps/dockerfile b/web-apps/dockerfile
index befdc18..115cac5 100644
--- a/web-apps/dockerfile
+++ b/web-apps/dockerfile
@@ -1,25 +1,29 @@
-FROM nextcloud:fpm-alpine
+FROM nextcloud:apache
 
 RUN set -ex; \
     \
-    apk add --no-cache \
+    apt-get update; \
+    apt-get install -y --no-install-recommends \
         ffmpeg \
-        imagemagick \
+        ghostscript \
+        libmagickcore-6.q16-6-extra \
         procps \
-        samba-client \
+        smbclient \
         supervisor \
 #       libreoffice \
-    ;
+    ; \
+    rm -rf /var/lib/apt/lists/*
 
 RUN set -ex; \
     \
-    apk add --no-cache --virtual .build-deps \
-        $PHPIZE_DEPS \
-        imap-dev \
-        krb5-dev \
-        openssl-dev \
-        samba-dev \
-        bzip2-dev \
+    savedAptMark="$(apt-mark showmanual)"; \
+    \
+    apt-get update; \
+    apt-get install -y --no-install-recommends \
+        libbz2-dev \
+        libc-client-dev \
+        libkrb5-dev \
+        libsmbclient-dev \
     ; \
     \
     docker-php-ext-configure imap --with-kerberos --with-imap-ssl; \
@@ -30,14 +34,19 @@ RUN set -ex; \
     pecl install smbclient; \
     docker-php-ext-enable smbclient; \
     \
-    runDeps="$( \
-        scanelf --needed --nobanner --format '%n#p' --recursive /usr/local/lib/php/extensions \
-            | tr ',' '\n' \
-            | sort -u \
-            | awk 'system("[ -e /usr/local/lib/" $1 " ]") == 0 { next } { print "so:" $1 }' \
-    )"; \
-    apk add --virtual .nextcloud-phpext-rundeps $runDeps; \
-    apk del .build-deps
+# 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 '/=>/ { so = $(NF-1); if (index(so, "/usr/local/") == 1) { next }; gsub("^/(usr/)?", "", so); print so }' \
+        | sort -u \
+        | xargs -r dpkg-query --search \
+        | 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/*
 
 RUN mkdir -p \
     /var/log/supervisord \