diff --git a/lib/actions/thread-actions.js b/lib/actions/thread-actions.js
--- a/lib/actions/thread-actions.js
+++ b/lib/actions/thread-actions.js
@@ -24,10 +24,7 @@
   ThreadInfo,
   RawThreadInfo,
 } from '../types/minimally-encoded-thread-permissions-types.js';
-import {
-  thickThreadTypes,
-  threadTypeIsThick,
-} from '../types/thread-types-enum.js';
+import { thickThreadTypes } from '../types/thread-types-enum.js';
 import type {
   ChangeThreadSettingsPayload,
   LeaveThreadPayload,
@@ -42,6 +39,7 @@
   RoleModificationPayload,
   RoleDeletionRequest,
   RoleDeletionPayload,
+  UpdaetThickThreadRequest,
 } from '../types/thread-types.js';
 import { values } from '../utils/objects.js';
 import { useSelector } from '../utils/redux-utils.js';
@@ -119,9 +117,21 @@
     };
   };
 
-function useChangeThreadSettings(
-  threadInfo: ?ThreadInfo,
-): (input: UpdateThreadRequest) => Promise<ChangeThreadSettingsPayload> {
+export type UseChangeThreadSettingsInput = $ReadOnly<
+  | {
+      ...UpdateThreadRequest,
+      +thick: false,
+    }
+  | {
+      ...UpdaetThickThreadRequest,
+      +thick: true,
+      +threadInfo: ThreadInfo,
+    },
+>;
+
+function useChangeThreadSettings(): (
+  input: UseChangeThreadSettingsInput,
+) => Promise<ChangeThreadSettingsPayload> {
   const processAndSendDMOperation = useProcessAndSendDMOperation();
   const viewerID = useSelector(
     state => state.currentUserInfo && state.currentUserInfo.id,
@@ -130,9 +140,10 @@
   const keyserverCall = useKeyserverCall(changeThreadSettings);
 
   return React.useCallback(
-    async (input: UpdateThreadRequest) => {
-      if (!threadInfo || !threadTypeIsThick(threadInfo.type)) {
-        return await keyserverCall(input);
+    async (input: UseChangeThreadSettingsInput) => {
+      if (!input.thick) {
+        const { thick, ...rest } = input;
+        return await keyserverCall({ ...rest });
       }
 
       invariant(viewerID, 'viewerID should be set');
@@ -159,7 +170,7 @@
       // To support `image` and `encrypted_image` avatars we first, need stop
       // sending multimedia metadata to keyserver.
       // ENG-8708
-
+      const { threadInfo } = input;
       const op: DMChangeThreadSettingsOperation = {
         type: 'change_thread_settings',
         threadID: threadInfo.id,
@@ -188,7 +199,7 @@
         newMessageInfos: [],
       }: ChangeThreadSettingsPayload);
     },
-    [keyserverCall, processAndSendDMOperation, threadInfo, viewerID],
+    [keyserverCall, processAndSendDMOperation, viewerID],
   );
 }
 
diff --git a/lib/components/base-edit-thread-avatar-provider.react.js b/lib/components/base-edit-thread-avatar-provider.react.js
--- a/lib/components/base-edit-thread-avatar-provider.react.js
+++ b/lib/components/base-edit-thread-avatar-provider.react.js
@@ -10,7 +10,7 @@
 import { threadInfoSelector } from '../selectors/thread-selectors.js';
 import type { UpdateUserAvatarRequest } from '../types/avatar-types.js';
 import type { LoadingStatus } from '../types/loading-types.js';
-import type { UpdateThreadRequest } from '../types/thread-types.js';
+import { threadTypeIsThick } from '../types/thread-types-enum.js';
 import { useDispatchActionPromise } from '../utils/redux-promise-utils.js';
 import { useSelector } from '../utils/redux-utils.js';
 
@@ -44,7 +44,7 @@
     state => threadInfoSelector(state)[activeThreadID],
   );
   const dispatchActionPromise = useDispatchActionPromise();
-  const changeThreadSettingsCall = useChangeThreadSettings(threadInfo);
+  const changeThreadSettingsCall = useChangeThreadSettings();
 
   const [
     threadAvatarMediaUploadInProgress,
@@ -73,7 +73,7 @@
   //       Use platform-specific `[web/native]SetThreadAvatar` instead.
   const baseSetThreadAvatar = React.useCallback(
     async (threadID: string, avatarRequest: UpdateUserAvatarRequest) => {
-      const updateThreadRequest: UpdateThreadRequest = {
+      const updateThreadRequest = {
         threadID,
         changes: {
           avatar: avatarRequest,
@@ -86,13 +86,18 @@
       ) {
         updateThreadAvatarMediaUploadInProgress(false);
       }
-      const promise = changeThreadSettingsCall(updateThreadRequest);
+      const updateThreadInput = threadTypeIsThick(threadInfo.type)
+        ? { thick: true, threadInfo, ...updateThreadRequest }
+        : { thick: false, ...updateThreadRequest };
+
+      const promise = changeThreadSettingsCall(updateThreadInput);
       void dispatchActionPromise(changeThreadSettingsActionTypes, promise, {
         customKeyName: `${action}:${threadID}:avatar`,
       });
       await promise;
     },
     [
+      threadInfo,
       changeThreadSettingsCall,
       dispatchActionPromise,
       updateThreadAvatarMediaUploadInProgress,
diff --git a/lib/hooks/promote-sidebar.react.js b/lib/hooks/promote-sidebar.react.js
--- a/lib/hooks/promote-sidebar.react.js
+++ b/lib/hooks/promote-sidebar.react.js
@@ -69,6 +69,7 @@
         changeThreadSettingsActionTypes,
         (async () => {
           return await callChangeThreadSettings({
+            thick: false,
             threadID: threadInfo.id,
             changes: { type: threadTypes.COMMUNITY_OPEN_SUBTHREAD },
           });
diff --git a/lib/shared/messages/text-message-spec.js b/lib/shared/messages/text-message-spec.js
--- a/lib/shared/messages/text-message-spec.js
+++ b/lib/shared/messages/text-message-spec.js
@@ -27,10 +27,14 @@
 } from '../../types/messages/text.js';
 import type { ThreadInfo } from '../../types/minimally-encoded-thread-permissions-types.js';
 import type { NotifTexts } from '../../types/notif-types.js';
-import { threadTypeIsSidebar } from '../../types/thread-types-enum.js';
+import {
+  threadTypeIsSidebar,
+  threadTypeIsThick,
+} from '../../types/thread-types-enum.js';
 import type { RelativeUserInfo } from '../../types/user-types.js';
 import { ET } from '../../utils/entity-text.js';
 import { useDispatchActionPromise } from '../../utils/redux-promise-utils.js';
+import { useAddDMThreadMembers } from '../dm-ops/dm-op-utils.js';
 import {
   type ASTNode,
   type SingleASTNode,
@@ -292,6 +296,7 @@
   useCreationSideEffectsFunc: () => {
     const dispatchActionPromise = useDispatchActionPromise();
     const callChangeThreadSettings = useChangeThreadSettings();
+    const callAddDMThreadMembers = useAddDMThreadMembers();
     return async (
       messageInfo: RawTextMessageInfo,
       threadInfo: ThreadInfo,
@@ -313,10 +318,24 @@
       }
 
       const newMemberIDs = mentionedNewMembers.map(({ id }) => id);
-      const addMembersPromise = callChangeThreadSettings({
+      if (threadTypeIsThick(threadInfo.type)) {
+        await callAddDMThreadMembers(newMemberIDs, threadInfo);
+        return;
+      }
+
+      const changeThreadSettingsRequest = {
         threadID: threadInfo.id,
         changes: { newMemberIDs },
-      });
+      };
+
+      const changeThreadSettingsInput = {
+        thick: false,
+        ...changeThreadSettingsRequest,
+      };
+
+      const addMembersPromise = callChangeThreadSettings(
+        changeThreadSettingsInput,
+      );
 
       void dispatchActionPromise(
         changeThreadSettingsActionTypes,
diff --git a/lib/types/thread-types.js b/lib/types/thread-types.js
--- a/lib/types/thread-types.js
+++ b/lib/types/thread-types.js
@@ -312,7 +312,7 @@
   },
 };
 
-export type ThreadChanges = Partial<{
+type BaseThreadChanges = {
   +type: ThinThreadType,
   +name: string,
   +description: string,
@@ -320,7 +320,13 @@
   +parentThreadID: ?string,
   +newMemberIDs: $ReadOnlyArray<string>,
   +avatar: UpdateUserAvatarRequest,
-}>;
+};
+
+export type ThreadChanges = Partial<BaseThreadChanges>;
+
+export type ThickThreadChanges = $ReadOnly<
+  $Partial<$Rest<BaseThreadChanges, { +newMemberIDs: $ReadOnlyArray<string> }>>,
+>;
 
 export type UpdateThreadRequest = {
   +threadID: string,
@@ -328,6 +334,11 @@
   +accountPassword?: empty,
 };
 
+export type UpdaetThickThreadRequest = $ReadOnly<{
+  ...UpdateThreadRequest,
+  +changes: ThickThreadChanges,
+}>;
+
 export type BaseNewThreadRequest = {
   +id?: ?string,
   +name?: ?string,
diff --git a/native/chat/settings/add-users-modal.react.js b/native/chat/settings/add-users-modal.react.js
--- a/native/chat/settings/add-users-modal.react.js
+++ b/native/chat/settings/add-users-modal.react.js
@@ -79,6 +79,7 @@
   const addUsersToThread = React.useCallback(async () => {
     try {
       const result = await callChangeThreadSettings({
+        thick: false,
         threadID: threadID,
         changes: { newMemberIDs: userInfoInputIDs },
       });
diff --git a/native/chat/settings/color-selector-modal.react.js b/native/chat/settings/color-selector-modal.react.js
--- a/native/chat/settings/color-selector-modal.react.js
+++ b/native/chat/settings/color-selector-modal.react.js
@@ -7,12 +7,11 @@
 import {
   changeThreadSettingsActionTypes,
   useChangeThreadSettings,
+  type UseChangeThreadSettingsInput,
 } from 'lib/actions/thread-actions.js';
 import type { ThreadInfo } from 'lib/types/minimally-encoded-thread-permissions-types.js';
-import {
-  type ChangeThreadSettingsPayload,
-  type UpdateThreadRequest,
-} from 'lib/types/thread-types.js';
+import { threadTypeIsThick } from 'lib/types/thread-types-enum.js';
+import { type ChangeThreadSettingsPayload } from 'lib/types/thread-types.js';
 import {
   type DispatchActionPromise,
   useDispatchActionPromise,
@@ -78,7 +77,7 @@
   +dispatchActionPromise: DispatchActionPromise,
   // async functions that hit server APIs
   +changeThreadSettings: (
-    request: UpdateThreadRequest,
+    input: UseChangeThreadSettingsInput,
   ) => Promise<ChangeThreadSettingsPayload>,
 };
 function ColorSelectorModal(props: Props): React.Node {
@@ -99,10 +98,21 @@
     async (newColor: string) => {
       const threadID = threadInfo.id;
       try {
-        return await updateThreadSettings({
+        const changeThreadSettingRequest = {
           threadID,
           changes: { color: newColor },
-        });
+        };
+
+        const changeThreadSettingInput = threadTypeIsThick(
+          props.route.params.threadInfo.type,
+        )
+          ? {
+              thick: true,
+              threadInfo: props.route.params.threadInfo,
+              ...changeThreadSettingRequest,
+            }
+          : { thick: false, ...changeThreadSettingRequest };
+        return await updateThreadSettings(changeThreadSettingInput);
       } catch (e) {
         Alert.alert(
           unknownErrorAlertDetails.title,
@@ -113,7 +123,12 @@
         throw e;
       }
     },
-    [onErrorAcknowledged, threadInfo.id, updateThreadSettings],
+    [
+      onErrorAcknowledged,
+      threadInfo.id,
+      updateThreadSettings,
+      props.route.params.threadInfo,
+    ],
   );
 
   const onColorSelected = React.useCallback(
@@ -176,9 +191,7 @@
     const windowWidth = useSelector(state => state.dimensions.width);
 
     const dispatchActionPromise = useDispatchActionPromise();
-    const callChangeThreadSettings = useChangeThreadSettings(
-      props.route.params.threadInfo,
-    );
+    const callChangeThreadSettings = useChangeThreadSettings();
 
     return (
       <ColorSelectorModal
diff --git a/native/chat/settings/thread-settings-description.react.js b/native/chat/settings/thread-settings-description.react.js
--- a/native/chat/settings/thread-settings-description.react.js
+++ b/native/chat/settings/thread-settings-description.react.js
@@ -12,16 +12,15 @@
 import {
   changeThreadSettingsActionTypes,
   useChangeThreadSettings,
+  type UseChangeThreadSettingsInput,
 } from 'lib/actions/thread-actions.js';
 import { createLoadingStatusSelector } from 'lib/selectors/loading-selectors.js';
 import { useThreadHasPermission } from 'lib/shared/thread-utils.js';
 import type { LoadingStatus } from 'lib/types/loading-types.js';
 import type { ThreadInfo } from 'lib/types/minimally-encoded-thread-permissions-types.js';
 import { threadPermissions } from 'lib/types/thread-permission-types.js';
-import {
-  type ChangeThreadSettingsPayload,
-  type UpdateThreadRequest,
-} from 'lib/types/thread-types.js';
+import { threadTypeIsThick } from 'lib/types/thread-types-enum.js';
+import { type ChangeThreadSettingsPayload } from 'lib/types/thread-types.js';
 import {
   type DispatchActionPromise,
   useDispatchActionPromise,
@@ -105,7 +104,7 @@
   +dispatchActionPromise: DispatchActionPromise,
   // async functions that hit server APIs
   +changeThreadSettings: (
-    update: UpdateThreadRequest,
+    input: UseChangeThreadSettingsInput,
   ) => Promise<ChangeThreadSettingsPayload>,
   +canEditThreadDescription: boolean,
 };
@@ -265,10 +264,22 @@
     newDescription: string,
   ): Promise<ChangeThreadSettingsPayload> {
     try {
-      return await this.props.changeThreadSettings({
+      const changeThreadSettingsRequest = {
         threadID: this.props.threadInfo.id,
         changes: { description: newDescription },
-      });
+      };
+
+      const changeThreadSettingsInput = threadTypeIsThick(
+        this.props.threadInfo.type,
+      )
+        ? {
+            thick: true,
+            threadInfo: this.props.threadInfo,
+            ...changeThreadSettingsRequest,
+          }
+        : { thick: false, ...changeThreadSettingsRequest };
+
+      return await this.props.changeThreadSettings(changeThreadSettingsInput);
     } catch (e) {
       Alert.alert(
         unknownErrorAlertDetails.title,
@@ -306,7 +317,7 @@
     const styles = useStyles(unboundStyles);
 
     const dispatchActionPromise = useDispatchActionPromise();
-    const callChangeThreadSettings = useChangeThreadSettings(props.threadInfo);
+    const callChangeThreadSettings = useChangeThreadSettings();
 
     const canEditThreadDescription = useThreadHasPermission(
       props.threadInfo,
diff --git a/native/chat/settings/thread-settings-name.react.js b/native/chat/settings/thread-settings-name.react.js
--- a/native/chat/settings/thread-settings-name.react.js
+++ b/native/chat/settings/thread-settings-name.react.js
@@ -12,14 +12,13 @@
 import {
   changeThreadSettingsActionTypes,
   useChangeThreadSettings,
+  type UseChangeThreadSettingsInput,
 } from 'lib/actions/thread-actions.js';
 import { createLoadingStatusSelector } from 'lib/selectors/loading-selectors.js';
 import type { LoadingStatus } from 'lib/types/loading-types.js';
 import type { ResolvedThreadInfo } from 'lib/types/minimally-encoded-thread-permissions-types.js';
-import type {
-  ChangeThreadSettingsPayload,
-  UpdateThreadRequest,
-} from 'lib/types/thread-types.js';
+import { threadTypeIsThick } from 'lib/types/thread-types-enum.js';
+import type { ChangeThreadSettingsPayload } from 'lib/types/thread-types.js';
 import {
   useDispatchActionPromise,
   type DispatchActionPromise,
@@ -77,7 +76,7 @@
   +dispatchActionPromise: DispatchActionPromise,
   // async functions that hit server APIs
   +changeThreadSettings: (
-    update: UpdateThreadRequest,
+    input: UseChangeThreadSettingsInput,
   ) => Promise<ChangeThreadSettingsPayload>,
 };
 class ThreadSettingsName extends React.PureComponent<Props> {
@@ -193,10 +192,22 @@
 
   async editName(newName: string): Promise<ChangeThreadSettingsPayload> {
     try {
-      return await this.props.changeThreadSettings({
+      const changeThreadSetingsRequest = {
         threadID: this.props.threadInfo.id,
         changes: { name: newName },
-      });
+      };
+
+      const changeThreadSettingsInput = threadTypeIsThick(
+        this.props.threadInfo.type,
+      )
+        ? {
+            thick: true,
+            threadInfo: this.props.threadInfo,
+            ...changeThreadSetingsRequest,
+          }
+        : { thick: false, ...changeThreadSetingsRequest };
+
+      return await this.props.changeThreadSettings(changeThreadSettingsInput);
     } catch (e) {
       Alert.alert(
         unknownErrorAlertDetails.title,
@@ -230,7 +241,7 @@
     );
 
     const dispatchActionPromise = useDispatchActionPromise();
-    const callChangeThreadSettings = useChangeThreadSettings(props.threadInfo);
+    const callChangeThreadSettings = useChangeThreadSettings();
 
     return (
       <ThreadSettingsName
diff --git a/web/modals/threads/members/add-members-modal.react.js b/web/modals/threads/members/add-members-modal.react.js
--- a/web/modals/threads/members/add-members-modal.react.js
+++ b/web/modals/threads/members/add-members-modal.react.js
@@ -75,6 +75,7 @@
       void dispatchActionPromise(
         changeThreadSettingsActionTypes,
         callChangeThreadSettings({
+          thick: false,
           threadID,
           changes: { newMemberIDs },
         }),
diff --git a/web/modals/threads/settings/thread-settings-general-tab.react.js b/web/modals/threads/settings/thread-settings-general-tab.react.js
--- a/web/modals/threads/settings/thread-settings-general-tab.react.js
+++ b/web/modals/threads/settings/thread-settings-general-tab.react.js
@@ -7,7 +7,7 @@
 import { type SetState } from 'lib/types/hook-types.js';
 import type { ThreadInfo } from 'lib/types/minimally-encoded-thread-permissions-types.js';
 import { threadPermissions } from 'lib/types/thread-permission-types.js';
-import { type ThreadChanges } from 'lib/types/thread-types.js';
+import { type ThickThreadChanges } from 'lib/types/thread-types.js';
 import { firstLine } from 'lib/utils/string-utils.js';
 import { chatNameMaxLength } from 'lib/utils/validation-utils.js';
 
@@ -20,8 +20,8 @@
   +threadSettingsOperationInProgress: boolean,
   +threadInfo: ThreadInfo,
   +threadNamePlaceholder: string,
-  +queuedChanges: ThreadChanges,
-  +setQueuedChanges: SetState<ThreadChanges>,
+  +queuedChanges: ThickThreadChanges,
+  +setQueuedChanges: SetState<ThickThreadChanges>,
 };
 function ThreadSettingsGeneralTab(
   props: ThreadSettingsGeneralTabProps,
diff --git a/web/modals/threads/settings/thread-settings-modal.react.js b/web/modals/threads/settings/thread-settings-modal.react.js
--- a/web/modals/threads/settings/thread-settings-modal.react.js
+++ b/web/modals/threads/settings/thread-settings-modal.react.js
@@ -20,7 +20,7 @@
 import type { RelationshipButton } from 'lib/types/relationship-types.js';
 import { threadPermissions } from 'lib/types/thread-permission-types.js';
 import { threadTypes } from 'lib/types/thread-types-enum.js';
-import { type ThreadChanges } from 'lib/types/thread-types.js';
+import { type ThickThreadChanges } from 'lib/types/thread-types.js';
 import { useResolvedThreadInfo } from 'lib/utils/entity-helpers.js';
 
 import ThreadSettingsDeleteButton from './thread-settings-delete-button.react.js';
@@ -60,9 +60,8 @@
     const [errorMessage, setErrorMessage] = React.useState<?string>('');
     const [currentTabType, setCurrentTabType] =
       React.useState<TabType>('general');
-    const [queuedChanges, setQueuedChanges] = React.useState<ThreadChanges>(
-      Object.freeze({}),
-    );
+    const [queuedChanges, setQueuedChanges] =
+      React.useState<ThickThreadChanges>(Object.freeze({}));
 
     const threadInfoWithNoName = React.useMemo(() => {
       invariant(threadInfo, 'threadInfo should exist in threadInfoWithNoName');
diff --git a/web/modals/threads/settings/thread-settings-privacy-tab.react.js b/web/modals/threads/settings/thread-settings-privacy-tab.react.js
--- a/web/modals/threads/settings/thread-settings-privacy-tab.react.js
+++ b/web/modals/threads/settings/thread-settings-privacy-tab.react.js
@@ -7,7 +7,7 @@
 import { type SetState } from 'lib/types/hook-types.js';
 import type { ThreadInfo } from 'lib/types/minimally-encoded-thread-permissions-types.js';
 import { threadTypes } from 'lib/types/thread-types-enum.js';
-import { type ThreadChanges } from 'lib/types/thread-types.js';
+import { type ThickThreadChanges } from 'lib/types/thread-types.js';
 
 import css from './thread-settings-privacy-tab.css';
 import EnumSettingsOption from '../../../components/enum-settings-option.react.js';
@@ -32,8 +32,8 @@
 
 type ThreadSettingsPrivacyTabProps = {
   +threadInfo: ThreadInfo,
-  +queuedChanges: ThreadChanges,
-  +setQueuedChanges: SetState<ThreadChanges>,
+  +queuedChanges: ThickThreadChanges,
+  +setQueuedChanges: SetState<ThickThreadChanges>,
 };
 function ThreadSettingsPrivacyTab(
   props: ThreadSettingsPrivacyTabProps,
diff --git a/web/modals/threads/settings/thread-settings-save-button.react.js b/web/modals/threads/settings/thread-settings-save-button.react.js
--- a/web/modals/threads/settings/thread-settings-save-button.react.js
+++ b/web/modals/threads/settings/thread-settings-save-button.react.js
@@ -4,7 +4,7 @@
 
 import type { SetState } from 'lib/types/hook-types.js';
 import type { ThreadInfo } from 'lib/types/minimally-encoded-thread-permissions-types.js';
-import type { ThreadChanges } from 'lib/types/thread-types.js';
+import type { ThickThreadChanges } from 'lib/types/thread-types.js';
 
 import {
   useOnSaveGeneralThreadSettings,
@@ -15,8 +15,8 @@
 type Props = {
   +activeTab: 'general' | 'privacy',
   +threadInfo: ThreadInfo,
-  +queuedChanges: ThreadChanges,
-  +setQueuedChanges: SetState<ThreadChanges>,
+  +queuedChanges: ThickThreadChanges,
+  +setQueuedChanges: SetState<ThickThreadChanges>,
   +setErrorMessage: SetState<?string>,
   +threadSettingsOperationInProgress: boolean,
 };
diff --git a/web/modals/threads/settings/thread-settings-utils.js b/web/modals/threads/settings/thread-settings-utils.js
--- a/web/modals/threads/settings/thread-settings-utils.js
+++ b/web/modals/threads/settings/thread-settings-utils.js
@@ -12,7 +12,8 @@
 import { containedThreadInfos } from 'lib/selectors/thread-selectors.js';
 import { type SetState } from 'lib/types/hook-types.js';
 import type { ThreadInfo } from 'lib/types/minimally-encoded-thread-permissions-types.js';
-import { type ThreadChanges } from 'lib/types/thread-types.js';
+import { threadTypeIsThick } from 'lib/types/thread-types-enum.js';
+import type { ThickThreadChanges } from 'lib/types/thread-types.js';
 import { useDispatchActionPromise } from 'lib/utils/redux-promise-utils.js';
 
 import ThreadDeleteConfirmationModal from './thread-settings-delete-confirmation-modal.react.js';
@@ -20,8 +21,8 @@
 
 type UseOnSaveGeneralThreadSettingsParams = {
   +threadInfo: ThreadInfo,
-  +queuedChanges: ThreadChanges,
-  +setQueuedChanges: SetState<ThreadChanges>,
+  +queuedChanges: ThickThreadChanges,
+  +setQueuedChanges: SetState<ThickThreadChanges>,
   +setErrorMessage: SetState<?string>,
 };
 
@@ -32,15 +33,25 @@
     params;
 
   const dispatchActionPromise = useDispatchActionPromise();
-  const callChangeThreadSettings = useChangeThreadSettings(threadInfo);
+  const callChangeThreadSettings = useChangeThreadSettings();
 
   const changeThreadSettingsAction = React.useCallback(async () => {
     try {
       setErrorMessage('');
-      return await callChangeThreadSettings({
+      const changeThreadSettingsRequest = {
         threadID: threadInfo.id,
         changes: queuedChanges,
-      });
+      };
+
+      const changeThreadSettingsInput = threadTypeIsThick(threadInfo.type)
+        ? {
+            thick: true,
+            threadInfo,
+            ...changeThreadSettingsRequest,
+          }
+        : { thick: false, ...changeThreadSettingsRequest };
+
+      return await callChangeThreadSettings(changeThreadSettingsInput);
     } catch (e) {
       setErrorMessage('unknown_error');
       throw e;
@@ -52,7 +63,7 @@
     queuedChanges,
     setErrorMessage,
     setQueuedChanges,
-    threadInfo.id,
+    threadInfo,
   ]);
 
   const onSubmit = React.useCallback(
@@ -71,8 +82,8 @@
 
 type UseOnSavePrivacySettingsParams = {
   +threadInfo: ThreadInfo,
-  +queuedChanges: ThreadChanges,
-  +setQueuedChanges: SetState<ThreadChanges>,
+  +queuedChanges: ThickThreadChanges,
+  +setQueuedChanges: SetState<ThickThreadChanges>,
   +setErrorMessage: SetState<?string>,
 };
 
@@ -90,6 +101,7 @@
     try {
       setErrorMessage('');
       const response = await callChangeThreadSettings({
+        thick: false,
         threadID: threadInfo.id,
         changes: queuedChanges,
       });