diff --git a/Gemfile b/Gemfile
index 8fd9fb3e277..713e5600e84 100644
--- a/Gemfile
+++ b/Gemfile
@@ -161,5 +161,3 @@ gem 'connection_pool', require: false
 
 gem 'xorcist', '~> 1.1'
 gem 'pluck_each', '~> 0.1.3'
-
-gem 'secure_headers', '~> 3.5'
diff --git a/Gemfile.lock b/Gemfile.lock
index 3780e3a29b5..e508b0b0c07 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -571,8 +571,6 @@ GEM
     scenic (1.5.4)
       activerecord (>= 4.0.0)
       railties (>= 4.0.0)
-    secure_headers (3.9.0)
-      useragent
     securecompare (1.0.0)
     semantic_range (2.3.0)
     sidekiq (6.1.3)
@@ -654,7 +652,6 @@ GEM
     unf_ext (0.0.7.7)
     unicode-display_width (1.7.0)
     uniform_notifier (1.13.2)
-    useragent (0.16.10)
     warden (1.2.9)
       rack (>= 2.0.9)
     webauthn (3.0.0.alpha1)
@@ -798,7 +795,6 @@ DEPENDENCIES
   ruby-progressbar (~> 1.11)
   sanitize (~> 5.2)
   scenic (~> 1.5)
-  secure_headers (~> 3.5)
   sidekiq (~> 6.1)
   sidekiq-bulk (~> 0.2.0)
   sidekiq-scheduler (~> 3.0)
diff --git a/config/application.rb b/config/application.rb
index a45ac186014..116eaf29d40 100644
--- a/config/application.rb
+++ b/config/application.rb
@@ -25,6 +25,7 @@ require_relative '../lib/devise/two_factor_pam_authenticatable'
 require_relative '../lib/chewy/strategy/custom_sidekiq'
 require_relative '../lib/webpacker/manifest_extensions'
 require_relative '../lib/webpacker/helper_extensions'
+require_relative '../lib/action_dispatch/cookie_jar_extensions'
 require_relative '../lib/rails/engine_extensions'
 
 Dotenv::Railtie.load
diff --git a/config/initializers/devise.rb b/config/initializers/devise.rb
index d3757b0d343..ef612e177de 100644
--- a/config/initializers/devise.rb
+++ b/config/initializers/devise.rb
@@ -9,6 +9,7 @@ Warden::Manager.after_set_user except: :fetch do |user, warden|
     value: session_id,
     expires: 1.year.from_now,
     httponly: true,
+    secure: (Rails.env.production? || ENV['LOCAL_HTTPS'] == 'true'),
     same_site: :lax,
   }
 end
@@ -19,6 +20,7 @@ Warden::Manager.after_fetch do |user, warden|
       value: warden.cookies.signed['_session_id'] || warden.raw_session['auth_id'],
       expires: 1.year.from_now,
       httponly: true,
+      secure: (Rails.env.production? || ENV['LOCAL_HTTPS'] == 'true'),
       same_site: :lax,
     }
   else
@@ -227,6 +229,10 @@ Devise.setup do |config|
   # If true, extends the user's remember period when remembered via cookie.
   # config.extend_remember_period = false
 
+  # Options to be passed to the created cookie. For instance, you can set
+  # secure: true in order to force SSL only cookies.
+  config.rememberable_options = { secure: true }
+
   # ==> Configuration for :validatable
   # Range for password length.
   config.password_length = 8..72
diff --git a/config/initializers/makara.rb b/config/initializers/makara.rb
index afd29eda8de..dc88fa63cd0 100644
--- a/config/initializers/makara.rb
+++ b/config/initializers/makara.rb
@@ -1 +1,2 @@
 Makara::Cookie::DEFAULT_OPTIONS[:same_site] = :lax
+Makara::Cookie::DEFAULT_OPTIONS[:secure]    = Rails.env.production? || ENV['LOCAL_HTTPS'] == 'true'
diff --git a/config/initializers/secureheaders.rb b/config/initializers/secureheaders.rb
deleted file mode 100644
index 6c8ac7fbe5e..00000000000
--- a/config/initializers/secureheaders.rb
+++ /dev/null
@@ -1,10 +0,0 @@
-SecureHeaders::Configuration.default do |config|
-  config.cookies = {
-    secure: true,
-    httponly: true,
-    samesite: {
-      lax: true
-    }
-  }
-  config.csp = SecureHeaders::OPT_OUT
-end
diff --git a/config/initializers/session_store.rb b/config/initializers/session_store.rb
index 7e3471ac4cb..e5d1be4c6c7 100644
--- a/config/initializers/session_store.rb
+++ b/config/initializers/session_store.rb
@@ -2,5 +2,6 @@
 
 Rails.application.config.session_store :cookie_store, {
   key: '_mastodon_session',
+  secure: (Rails.env.production? || ENV['LOCAL_HTTPS'] == 'true'),
   same_site: :lax,
 }
diff --git a/lib/action_dispatch/cookie_jar_extensions.rb b/lib/action_dispatch/cookie_jar_extensions.rb
new file mode 100644
index 00000000000..44c39c1f805
--- /dev/null
+++ b/lib/action_dispatch/cookie_jar_extensions.rb
@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+module ActionDispatch
+  module CookieJarExtensions
+    private
+
+    # Monkey-patch ActionDispatch to serve secure cookies to Tor Hidden Service
+    # users. Otherwise, ActionDispatch would drop the cookie over HTTP.
+    def write_cookie?(*)
+      request.headers['Host'].ends_with?('.onion') || super
+    end
+  end
+end
+
+ActionDispatch::Cookies::CookieJar.prepend(ActionDispatch::CookieJarExtensions)