diff --git a/app/javascript/mastodon/features/ui/components/visibility_modal.tsx b/app/javascript/mastodon/features/ui/components/visibility_modal.tsx
index 8b48cad5401..e8570dcb93f 100644
--- a/app/javascript/mastodon/features/ui/components/visibility_modal.tsx
+++ b/app/javascript/mastodon/features/ui/components/visibility_modal.tsx
@@ -89,6 +89,24 @@ const selectStatusPolicy = createAppSelector(
   },
 );
 
+const selectDisablePublicVisibilities = createAppSelector(
+  [
+    (state) => state.statuses,
+    (_state, statusId?: string) => !!statusId,
+    (state) => state.compose.get('quoted_status_id') as string | null,
+  ],
+  (statuses, isEditing, statusId) => {
+    if (isEditing || !statusId) return false;
+
+    const status = statuses.get(statusId);
+    if (!status) {
+      return false;
+    }
+
+    return status.get('visibility') === 'private';
+  },
+);
+
 export const VisibilityModal: FC<VisibilityModalProps> = forwardRef(
   // eslint-disable-next-line @typescript-eslint/no-unused-vars
   ({ onClose, onChange, statusId }, _ref) => {
@@ -110,24 +128,12 @@ export const VisibilityModal: FC<VisibilityModalProps> = forwardRef(
     const disableVisibility = !!statusId;
     const disableQuotePolicy =
       visibility === 'private' || visibility === 'direct';
+    const disablePublicVisibilities: boolean = useAppSelector(
+      selectDisablePublicVisibilities,
+    );
 
-    const visibilityItems = useMemo<SelectItem<StatusVisibility>[]>(
-      () => [
-        {
-          value: 'public',
-          text: intl.formatMessage(privacyMessages.public_short),
-          meta: intl.formatMessage(privacyMessages.public_long),
-          icon: 'globe',
-          iconComponent: PublicIcon,
-        },
-        {
-          value: 'unlisted',
-          text: intl.formatMessage(privacyMessages.unlisted_short),
-          meta: intl.formatMessage(privacyMessages.unlisted_long),
-          extra: intl.formatMessage(privacyMessages.unlisted_extra),
-          icon: 'unlock',
-          iconComponent: QuietTimeIcon,
-        },
+    const visibilityItems = useMemo<SelectItem<StatusVisibility>[]>(() => {
+      const items: SelectItem<StatusVisibility>[] = [
         {
           value: 'private',
           text: intl.formatMessage(privacyMessages.private_short),
@@ -142,9 +148,30 @@ export const VisibilityModal: FC<VisibilityModalProps> = forwardRef(
           icon: 'at',
           iconComponent: AlternateEmailIcon,
         },
-      ],
-      [intl],
-    );
+      ];
+
+      if (!disablePublicVisibilities) {
+        items.unshift(
+          {
+            value: 'public',
+            text: intl.formatMessage(privacyMessages.public_short),
+            meta: intl.formatMessage(privacyMessages.public_long),
+            icon: 'globe',
+            iconComponent: PublicIcon,
+          },
+          {
+            value: 'unlisted',
+            text: intl.formatMessage(privacyMessages.unlisted_short),
+            meta: intl.formatMessage(privacyMessages.unlisted_long),
+            extra: intl.formatMessage(privacyMessages.unlisted_extra),
+            icon: 'unlock',
+            iconComponent: QuietTimeIcon,
+          },
+        );
+      }
+
+      return items;
+    }, [intl, disablePublicVisibilities]);
     const quoteItems = useMemo<SelectItem<ApiQuotePolicy>[]>(
       () => [
         { value: 'public', text: intl.formatMessage(messages.quotePublic) },
@@ -236,6 +263,14 @@ export const VisibilityModal: FC<VisibilityModalProps> = forwardRef(
                   />
                 </p>
               )}
+              {!statusId && disablePublicVisibilities && (
+                <p className='visibility-dropdown__helper'>
+                  <FormattedMessage
+                    id='visibility_modal.helper.privacy_private_self_quote'
+                    defaultMessage='Self-quotes of private posts cannot be made public.'
+                  />
+                </p>
+              )}
             </label>
 
             <label
diff --git a/app/javascript/mastodon/locales/en.json b/app/javascript/mastodon/locales/en.json
index 46c979217a7..f2f23e60fa2 100644
--- a/app/javascript/mastodon/locales/en.json
+++ b/app/javascript/mastodon/locales/en.json
@@ -989,6 +989,7 @@
   "visibility_modal.header": "Visibility and interaction",
   "visibility_modal.helper.direct_quoting": "Private mentions authored on Mastodon can't be quoted by others.",
   "visibility_modal.helper.privacy_editing": "Published posts cannot change their visibility.",
+  "visibility_modal.helper.privacy_private_self_quote": "Self-quotes of private posts cannot be made public.",
   "visibility_modal.helper.private_quoting": "Follower-only posts authored on Mastodon can't be quoted by others.",
   "visibility_modal.helper.unlisted_quoting": "When people quote you, their post will also be hidden from trending timelines.",
   "visibility_modal.instructions": "Control who can interact with this post. You can also apply settings to all future posts by navigating to <link>Preferences > Posting defaults</link>.",
diff --git a/app/javascript/mastodon/reducers/compose.js b/app/javascript/mastodon/reducers/compose.js
index 7f9fc9eeaa2..f27c3bb06bf 100644
--- a/app/javascript/mastodon/reducers/compose.js
+++ b/app/javascript/mastodon/reducers/compose.js
@@ -334,7 +334,8 @@ export const composeReducer = (state = initialState, action) => {
     return state
       .set('quoted_status_id', status.get('id'))
       .set('spoiler', status.get('sensitive'))
-      .set('spoiler_text', status.get('spoiler_text'));
+      .set('spoiler_text', status.get('spoiler_text'))
+      .update('privacy', (visibility) => ['public', 'unlisted'].includes(visibility) && status.get('visibility') === 'private' ? 'private' : visibility);
   } else if (quoteComposeCancel.match(action)) {
     return state.set('quoted_status_id', null);
   } else if (setComposeQuotePolicy.match(action)) {
diff --git a/app/models/concerns/status/interaction_policy_concern.rb b/app/models/concerns/status/interaction_policy_concern.rb
index 2f8c75e740b..28a568e902d 100644
--- a/app/models/concerns/status/interaction_policy_concern.rb
+++ b/app/models/concerns/status/interaction_policy_concern.rb
@@ -27,7 +27,7 @@ module Status::InteractionPolicyConcern
 
   # Returns `:automatic`, `:manual`, `:unknown` or `:denied`
   def quote_policy_for_account(other_account, preloaded_relations: {})
-    return :denied if other_account.nil?
+    return :denied if other_account.nil? || direct_visibility?
 
     following_author = nil
 
diff --git a/app/services/post_status_service.rb b/app/services/post_status_service.rb
index acf6126ccfe..cfc80d81cd3 100644
--- a/app/services/post_status_service.rb
+++ b/app/services/post_status_service.rb
@@ -69,6 +69,7 @@ class PostStatusService < BaseService
     @text         = @options.delete(:spoiler_text) if @text.blank? && @options[:spoiler_text].present?
     @visibility   = @options[:visibility] || @account.user&.setting_default_privacy
     @visibility   = :unlisted if @visibility&.to_sym == :public && @account.silenced?
+    @visibility   = :private if @quoted_status&.private_visibility?
     @scheduled_at = @options[:scheduled_at]&.to_datetime
     @scheduled_at = nil if scheduled_in_the_past?
   rescue ArgumentError
diff --git a/spec/policies/status_policy_spec.rb b/spec/policies/status_policy_spec.rb
index af6958b68dc..eb79aa6fcd1 100644
--- a/spec/policies/status_policy_spec.rb
+++ b/spec/policies/status_policy_spec.rb
@@ -88,10 +88,10 @@ RSpec.describe StatusPolicy, type: :model do
 
   context 'with the permission of quote?' do
     permissions :quote? do
-      it 'grants access when direct and account is viewer' do
+      it 'does not grant access when direct and account is viewer' do
         status.visibility = :direct
 
-        expect(subject).to permit(status.account, status)
+        expect(subject).to_not permit(status.account, status)
       end
 
       it 'does not grant access access when direct and viewer is mentioned but not explicitly allowed' do
diff --git a/spec/services/post_status_service_spec.rb b/spec/services/post_status_service_spec.rb
index 64bb5e32e21..5494fa0cadf 100644
--- a/spec/services/post_status_service_spec.rb
+++ b/spec/services/post_status_service_spec.rb
@@ -305,6 +305,14 @@ RSpec.describe PostStatusService do
       .to enqueue_sidekiq_job(ActivityPub::QuoteRequestWorker)
   end
 
+  it 'correctly downgrades visibility for private self-quotes' do
+    account = Fabricate(:account)
+    quoted_status = Fabricate(:status, account: account, visibility: :private)
+
+    status = subject.call(account, text: 'test', quoted_status: quoted_status)
+    expect(status).to be_private_visibility
+  end
+
   it 'returns existing status when used twice with idempotency key' do
     account = Fabricate(:account)
     status1 = subject.call(account, text: 'test', idempotency: 'meepmeep')