diff --git a/roles/common/tasks/main.yml b/roles/common/tasks/main.yml
index a12ab54..7a05124 100644
--- a/roles/common/tasks/main.yml
+++ b/roles/common/tasks/main.yml
@@ -57,5 +57,7 @@
      - yarn
      - libidn11-dev
      - libicu-dev
+     - libjemalloc1
+     - libjemalloc-dev
 - name: Add mastodon system user
   user: name=mastodon state=present
diff --git a/roles/ruby/tasks/main.yml b/roles/ruby/tasks/main.yml
index 9d2e5cb..d60d378 100644
--- a/roles/ruby/tasks/main.yml
+++ b/roles/ruby/tasks/main.yml
@@ -34,5 +34,6 @@
     executable: /bin/bash
   environment:
     PATH: '/home/mastodon/.rbenv/bin:/home/mastodon/.rbenv/shims:/home/mastodon/.rbenv/plugins/ruby-build/bin:{{ ansible_env.PATH }}'
+    RUBY_CONFIGURE_OPTS: '--with-jemalloc'
   become: true
   become_user: mastodon