diff --git a/webmails/Dockerfile b/webmails/Dockerfile
index 8fd6f9f8..fed0f464 100644
--- a/webmails/Dockerfile
+++ b/webmails/Dockerfile
@@ -11,7 +11,7 @@ COPY roundcube/pubkey.asc /tmp/roundcube.asc
 RUN set -euxo pipefail \
   ; apk add --no-cache \
     nginx gpg gpg-agent \
-    php81 php81-fpm php81-mbstring php81-zip php81-xml php81-simplexml \
+    php81 php81-fpm php81-mbstring php81-zip php81-xml php81-simplexml php81-pecl-apc \
     php81-dom php81-curl php81-exif gd php81-gd php81-iconv php81-intl php81-openssl \
     php81-pdo_sqlite php81-pdo_mysql php81-pdo_pgsql php81-pdo php81-sodium libsodium php81-tidy php81-pecl-uuid \
     php81-pspell php81-pecl-imagick php81-opcache php81-session php81-sockets php81-fileinfo \