diff --git a/config/docker/Dockerfile.danbooru b/config/docker/Dockerfile.danbooru
index e65e0e8ea..746eb4d4e 100644
--- a/config/docker/Dockerfile.danbooru
+++ b/config/docker/Dockerfile.danbooru
@@ -3,10 +3,6 @@ FROM ubuntu:21.04 AS base
 WORKDIR /danbooru
 ENV PATH="/root/.asdf/bin:/root/.asdf/shims:$PATH:/usr/lib/postgresql/14/bin"
 
-# Reduces memory usage at the cost of higher thread contention.
-# https://bugs.ruby-lang.org/issues/14718
-ENV MALLOC_ARENA_MAX=2
-
 COPY config/docker/build-base-image.sh .
 
 RUN \
@@ -64,6 +60,8 @@ RUN \
 
 FROM base as production
 
+ENV LD_PRELOAD=/usr/lib/x86_64-linux-gnu/libjemalloc.so.2
+
 COPY --from=development /root /root
 COPY --from=development /danbooru /danbooru
 
diff --git a/config/docker/build-base-image.sh b/config/docker/build-base-image.sh
index 0e3a60303..e3dba7600 100755
--- a/config/docker/build-base-image.sh
+++ b/config/docker/build-base-image.sh
@@ -25,7 +25,7 @@ DANBOORU_RUNTIME_DEPS="
   ca-certificates mkvtoolnix rclone libpq5 openssl libgmpxx4ldbl
   zlib1g libfftw3-3 libwebp6 libwebpmux3 libwebpdemux2 liborc-0.4.0 liblcms2-2
   libpng16-16 libexpat1 libglib2.0 libgif7 libexif12 libheif1 libvpx6
-  libseccomp2 libseccomp-dev
+  libseccomp2 libseccomp-dev libjemalloc2
 "
 COMMON_RUNTIME_DEPS="
   $DANBOORU_RUNTIME_DEPS $EXIFTOOL_RUNTIME_DEPS tini busybox less ncdu