diff --git a/app/javascript/packs/admin.js b/app/javascript/packs/admin.js
index 1c44fb45b..8fd1b8a8e 100644
--- a/app/javascript/packs/admin.js
+++ b/app/javascript/packs/admin.js
@@ -67,10 +67,36 @@ const onEnableBootstrapTimelineAccountsChange = (target) => {
 
 delegate(document, '#form_admin_settings_enable_bootstrap_timeline_accounts', 'change', ({ target }) => onEnableBootstrapTimelineAccountsChange(target));
 
+const onChangeRegistrationMode = (target) => {
+  const enabled = target.value === 'approved';
+
+  [].forEach.call(document.querySelectorAll('#form_admin_settings_require_invite_text'), (input) => {
+    input.disabled = !enabled;
+    if (enabled) {
+      let element = input;
+      do {
+        element.classList.remove('disabled');
+        element = element.parentElement;
+      } while (element && !element.classList.contains('fields-group'));
+    } else {
+      let element = input;
+      do {
+        element.classList.add('disabled');
+        element = element.parentElement;
+      } while (element && !element.classList.contains('fields-group'));
+    }
+  });
+};
+
+delegate(document, '#form_admin_settings_registrations_mode', 'change', ({ target }) => onChangeRegistrationMode(target));
+
 ready(() => {
   const domainBlockSeverityInput = document.getElementById('domain_block_severity');
   if (domainBlockSeverityInput) onDomainBlockSeverityChange(domainBlockSeverityInput);
 
   const enableBootstrapTimelineAccounts = document.getElementById('form_admin_settings_enable_bootstrap_timeline_accounts');
   if (enableBootstrapTimelineAccounts) onEnableBootstrapTimelineAccountsChange(enableBootstrapTimelineAccounts);
+
+  const registrationMode = document.getElementById('form_admin_settings_registrations_mode');
+  if (registrationMode) onChangeRegistrationMode(registrationMode);
 });
diff --git a/app/javascript/styles/mastodon/forms.scss b/app/javascript/styles/mastodon/forms.scss
index 92d89e6f2..e0604303b 100644
--- a/app/javascript/styles/mastodon/forms.scss
+++ b/app/javascript/styles/mastodon/forms.scss
@@ -377,11 +377,6 @@ code {
       box-shadow: none;
     }
 
-    &:focus:invalid:not(:placeholder-shown),
-    &:required:invalid:not(:placeholder-shown) {
-      border-color: lighten($error-red, 12%);
-    }
-
     &:required:valid {
       border-color: $valid-value-color;
     }
@@ -397,6 +392,16 @@ code {
     }
   }
 
+  input[type=text],
+  input[type=number],
+  input[type=email],
+  input[type=password] {
+    &:focus:invalid:not(:placeholder-shown),
+    &:required:invalid:not(:placeholder-shown) {
+      border-color: lighten($error-red, 12%);
+    }
+  }
+
   .input.field_with_errors {
     label {
       color: lighten($error-red, 12%);
diff --git a/app/models/form/admin_settings.rb b/app/models/form/admin_settings.rb
index 390836f28..e9f78da21 100644
--- a/app/models/form/admin_settings.rb
+++ b/app/models/form/admin_settings.rb
@@ -35,6 +35,7 @@ class Form::AdminSettings
     show_domain_blocks
     show_domain_blocks_rationale
     noindex
+    require_invite_text
   ).freeze
 
   BOOLEAN_KEYS = %i(
@@ -51,6 +52,7 @@ class Form::AdminSettings
     trends
     trendable_by_default
     noindex
+    require_invite_text
   ).freeze
 
   UPLOAD_KEYS = %i(
diff --git a/app/models/user.rb b/app/models/user.rb
index 981dc6d47..6088f1994 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -82,7 +82,8 @@ class User < ApplicationRecord
   has_many :webauthn_credentials, dependent: :destroy
 
   has_one :invite_request, class_name: 'UserInviteRequest', inverse_of: :user, dependent: :destroy
-  accepts_nested_attributes_for :invite_request, reject_if: ->(attributes) { attributes['text'].blank? }
+  accepts_nested_attributes_for :invite_request, reject_if: ->(attributes) { attributes['text'].blank? && !Setting.require_invite_text }
+  validates :invite_request, presence: true, on: :create, if: -> { Setting.require_invite_text }
 
   validates :locale, inclusion: I18n.available_locales.map(&:to_s), if: :locale?
   validates_with BlacklistedEmailValidator, on: :create
diff --git a/app/views/about/_registration.html.haml b/app/views/about/_registration.html.haml
index 6160ca4d4..e4d614d71 100644
--- a/app/views/about/_registration.html.haml
+++ b/app/views/about/_registration.html.haml
@@ -16,7 +16,7 @@
     - if approved_registrations?
       .fields-group
         = f.simple_fields_for :invite_request do |invite_request_fields|
-          = invite_request_fields.input :text, as: :text, wrapper: :with_block_label, required: false
+          = invite_request_fields.input :text, as: :text, wrapper: :with_block_label, required: Setting.require_invite_text
 
     .fields-group
       = f.input :agreement, as: :boolean, wrapper: :with_label, label: t('auth.checkbox_agreement_html', rules_path: about_more_path, terms_path: terms_path), required: true, disabled: closed_registrations?
diff --git a/app/views/admin/settings/edit.html.haml b/app/views/admin/settings/edit.html.haml
index 9e28766b1..a162490b5 100644
--- a/app/views/admin/settings/edit.html.haml
+++ b/app/views/admin/settings/edit.html.haml
@@ -43,6 +43,12 @@
 
   %hr.spacer/
 
+  .fields-group
+    = f.input :require_invite_text, as: :boolean, wrapper: :with_label, label: t('admin.settings.registrations.require_invite_text.title'), hint: t('admin.settings.registrations.require_invite_text.desc_html'), disabled: !approved_registrations?
+  .fields-group
+
+  %hr.spacer/
+
   .fields-group
     = f.input :enable_bootstrap_timeline_accounts, as: :boolean, wrapper: :with_label, label: t('admin.settings.enable_bootstrap_timeline_accounts.title')
   .fields-group
diff --git a/app/views/auth/registrations/new.html.haml b/app/views/auth/registrations/new.html.haml
index de541847f..6981195ed 100644
--- a/app/views/auth/registrations/new.html.haml
+++ b/app/views/auth/registrations/new.html.haml
@@ -31,7 +31,7 @@
   - if approved_registrations? && !@invite.present?
     .fields-group
       = f.simple_fields_for :invite_request, resource.invite_request || resource.build_invite_request do |invite_request_fields|
-        = invite_request_fields.input :text, as: :text, wrapper: :with_block_label, required: false
+        = invite_request_fields.input :text, as: :text, wrapper: :with_block_label, required: Setting.require_invite_text
 
   = f.input :invite_code, as: :hidden
 
diff --git a/config/locales/en.yml b/config/locales/en.yml
index f89f50e4d..114f86fd1 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -586,6 +586,9 @@ en:
         min_invite_role:
           disabled: No one
           title: Allow invitations by
+        require_invite_text:
+          desc_html: When registrations require manual approval, make the “Why do you want to join?” invite request text mandatory rather than optional
+          title: Require new users to fill an invite request text
       registrations_mode:
         modes:
           approved: Approval required for sign up
diff --git a/config/settings.yml b/config/settings.yml
index 217745f28..9cf68a096 100644
--- a/config/settings.yml
+++ b/config/settings.yml
@@ -70,6 +70,7 @@ defaults: &defaults
   spam_check_enabled: true
   show_domain_blocks: 'disabled'
   show_domain_blocks_rationale: 'disabled'
+  require_invite_text: false
 
 development:
   <<: *defaults