diff --git a/config/settings.yml b/config/settings.yml
index 84c592d..4fa90f0 100644
--- a/config/settings.yml
+++ b/config/settings.yml
@@ -1,6 +1,6 @@
 discourse_affiliate:
   affiliate_enabled:
-    default: true
+    default: false
     client: true
   affiliate_amazon_ca:
     default: ""
diff --git a/db/migrate/20250721192553_enable_affiliate_if_already_installed.rb b/db/migrate/20250721192553_enable_affiliate_if_already_installed.rb
new file mode 100644
index 0000000..bd691a6
--- /dev/null
+++ b/db/migrate/20250721192553_enable_affiliate_if_already_installed.rb
@@ -0,0 +1,45 @@
+# frozen_string_literal: true
+
+class EnableAffiliateIfAlreadyInstalled < ActiveRecord::Migration[7.2]
+  CONFIG_SETTINGS = %w[
+    affiliate_amazon_ca
+    affiliate_amazon_cn
+    affiliate_amazon_co_jp
+    affiliate_amazon_co_uk
+    affiliate_amazon_com
+    affiliate_amazon_com_au
+    affiliate_amazon_com_br
+    affiliate_amazon_com_mx
+    affiliate_amazon_de
+    affiliate_amazon_es
+    affiliate_amazon_fr
+    affiliate_amazon_in
+    affiliate_amazon_it
+    affiliate_amazon_nl
+    affiliate_amazon_eu
+    affiliate_ldlc_com
+  ].freeze
+
+  def up
+    is_configured = DB.query_single(<<~SQL, CONFIG_SETTINGS)&.first
+      SELECT 1 FROM site_settings
+      WHERE name IN (?)
+      AND value != ''
+      LIMIT 1
+    SQL
+
+    if is_configured
+      # The plugin was installed before we changed it to be disabled-by-default
+      # Therefore, if there is no existing database value, enable the plugin
+      execute <<~SQL
+        INSERT INTO site_settings(name, data_type, value, created_at, updated_at)
+        VALUES('affiliate_enabled', 5, 't', NOW(), NOW())
+        ON CONFLICT (name) DO NOTHING
+      SQL
+    end
+  end
+
+  def down
+    raise ActiveRecord::IrreversibleMigration
+  end
+end
diff --git a/spec/db/migrate/20250721192553_enable_affiliate_if_already_installed_spec.rb b/spec/db/migrate/20250721192553_enable_affiliate_if_already_installed_spec.rb
new file mode 100644
index 0000000..de28b26
--- /dev/null
+++ b/spec/db/migrate/20250721192553_enable_affiliate_if_already_installed_spec.rb
@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+require_relative "../../../db/migrate/20250721192553_enable_affiliate_if_already_installed"
+
+RSpec.describe EnableAffiliateIfAlreadyInstalled do
+  let(:connection) { ActiveRecord::Base.connection }
+
+  before do
+    @provider = SiteSetting.provider
+    SiteSetting.provider = SiteSettings::DbProvider.new(SiteSetting)
+  end
+
+  after { SiteSetting.provider = @provider }
+
+  it "enables the affiliate plugin if it was previously installed" do
+    expect(SiteSetting.affiliate_enabled).to eq(false)
+    SiteSetting.affiliate_amazon_ca = "abc"
+
+    EnableAffiliateIfAlreadyInstalled.new.up
+
+    SiteSetting.refresh!
+    expect(SiteSetting.affiliate_enabled).to eq(true)
+  end
+
+  it "leaves disabled if not configured" do
+    expect(SiteSetting.affiliate_enabled).to eq(false)
+
+    EnableAffiliateIfAlreadyInstalled.new.up
+
+    SiteSetting.refresh!
+    expect(SiteSetting.affiliate_enabled).to eq(false)
+  end
+end
diff --git a/spec/lib/affiliate_processor_spec.rb b/spec/lib/affiliate_processor_spec.rb
index 38eac35..fb074f2 100644
--- a/spec/lib/affiliate_processor_spec.rb
+++ b/spec/lib/affiliate_processor_spec.rb
@@ -5,6 +5,8 @@ def r(url)
     AffiliateProcessor.apply(url)
   end
 
+  before { enable_current_plugin }
+
   it "can apply affiliate code to ldlc" do
     SiteSetting.affiliate_ldlc_com = "samsshop"