diff --git a/keyserver/src/creators/thread-creator.js b/keyserver/src/creators/thread-creator.js
--- a/keyserver/src/creators/thread-creator.js
+++ b/keyserver/src/creators/thread-creator.js
@@ -195,7 +195,7 @@
     validateMembers: { initialMemberIDs, ghostMemberIDs },
   } = await promiseAll(checkPromises);
 
-  if (sourceMessage && isInvalidSidebarSource(sourceMessage.type)) {
+  if (sourceMessage && isInvalidSidebarSource(sourceMessage)) {
     throw new ServerError('invalid_parameters');
   }
 
diff --git a/keyserver/src/fetchers/message-fetchers.js b/keyserver/src/fetchers/message-fetchers.js
--- a/keyserver/src/fetchers/message-fetchers.js
+++ b/keyserver/src/fetchers/message-fetchers.js
@@ -5,6 +5,7 @@
 import {
   sortMessageInfoList,
   shimUnsupportedRawMessageInfos,
+  isInvalidSidebarSource,
 } from 'lib/shared/message-utils.js';
 import { messageSpecs } from 'lib/shared/messages/message-specs.js';
 import { getNotifCollapseKey } from 'lib/shared/notif-utils.js';
@@ -26,7 +27,6 @@
   defaultMaxMessageAge,
   type FetchPinnedMessagesRequest,
   type FetchPinnedMessagesResult,
-  isMessageSidebarSourceReactionEditOrPin,
   type SearchMessagesResponse,
 } from 'lib/types/message-types.js';
 import { defaultNumberPerThread } from 'lib/types/message-types.js';
@@ -745,7 +745,7 @@
   for (const message of messages) {
     let { rawMessageInfo } = message;
     invariant(
-      !isMessageSidebarSourceReactionEditOrPin(rawMessageInfo),
+      !isInvalidSidebarSource(rawMessageInfo),
       'SIDEBAR_SOURCE or TOGGLE_PIN should not point to a ' +
         'SIDEBAR_SOURCE, REACTION, EDIT_MESSAGE or TOGGLE_PIN',
     );
@@ -890,7 +890,7 @@
   >();
   for (const message of parsedResults) {
     const { rawMessageInfo } = message;
-    if (isMessageSidebarSourceReactionEditOrPin(rawMessageInfo)) {
+    if (isInvalidSidebarSource(rawMessageInfo)) {
       continue;
     }
     invariant(rawMessageInfo.id, 'rawMessageInfo.id should not be null');
diff --git a/lib/shared/message-utils.js b/lib/shared/message-utils.js
--- a/lib/shared/message-utils.js
+++ b/lib/shared/message-utils.js
@@ -653,12 +653,14 @@
   return `${localIDPrefix}${nextLocalID}`;
 }
 
-function isInvalidSidebarSource(messageType: number): boolean {
+function isInvalidSidebarSource(
+  message: RawMessageInfo | MessageInfo,
+): boolean %checks {
   return (
-    messageType === messageTypes.REACTION ||
-    messageType === messageTypes.EDIT_MESSAGE ||
-    messageType === messageTypes.SIDEBAR_SOURCE ||
-    messageType === messageTypes.TOGGLE_PIN
+    message.type === messageTypes.REACTION ||
+    message.type === messageTypes.EDIT_MESSAGE ||
+    message.type === messageTypes.SIDEBAR_SOURCE ||
+    message.type === messageTypes.TOGGLE_PIN
   );
 }
 
diff --git a/lib/shared/message-utils.test.js b/lib/shared/message-utils.test.js
--- a/lib/shared/message-utils.test.js
+++ b/lib/shared/message-utils.test.js
@@ -2,22 +2,417 @@
 
 import { isInvalidSidebarSource } from './message-utils.js';
 import { messageTypes } from '../types/message-types-enum.js';
-import { values } from '../utils/objects.js';
+import type { RawSidebarSourceMessageInfo } from '../types/message-types.js';
+import type { RawAddMembersMessageInfo } from '../types/messages/add-members.js';
+import type { RawChangeRoleMessageInfo } from '../types/messages/change-role.js';
+import type { RawChangeSettingsMessageInfo } from '../types/messages/change-settings.js';
+import type { RawCreateEntryMessageInfo } from '../types/messages/create-entry.js';
+import type { RawCreateSidebarMessageInfo } from '../types/messages/create-sidebar.js';
+import type { RawCreateSubthreadMessageInfo } from '../types/messages/create-subthread.js';
+import type { RawCreateThreadMessageInfo } from '../types/messages/create-thread.js';
+import type { RawDeleteEntryMessageInfo } from '../types/messages/delete-entry.js';
+import type { RawEditEntryMessageInfo } from '../types/messages/edit-entry.js';
+import type { RawEditMessageInfo } from '../types/messages/edit.js';
+import type { RawImagesMessageInfo } from '../types/messages/images.js';
+import type { RawJoinThreadMessageInfo } from '../types/messages/join-thread.js';
+import type { RawLeaveThreadMessageInfo } from '../types/messages/leave-thread.js';
+import type { RawMediaMessageInfo } from '../types/messages/media.js';
+import type { RawReactionMessageInfo } from '../types/messages/reaction.js';
+import type { RawRemoveMembersMessageInfo } from '../types/messages/remove-members.js';
+import type { RawRestoreEntryMessageInfo } from '../types/messages/restore-entry.js';
+import type { RawTextMessageInfo } from '../types/messages/text.js';
+import type { RawTogglePinMessageInfo } from '../types/messages/toggle-pin.js';
+import type { RawUpdateRelationshipMessageInfo } from '../types/messages/update-relationship.js';
+import { threadTypes } from '../types/thread-types-enum.js';
 
 describe('isInvalidSidebarSource', () => {
-  it('should return true for all message types except for the ones listed', () => {
-    values(messageTypes).forEach(messageType => {
-      const shouldBeInvalidSidebarSource = isInvalidSidebarSource(messageType);
-      if (
-        messageType === messageTypes.REACTION ||
-        messageType === messageTypes.EDIT_MESSAGE ||
-        messageType === messageTypes.SIDEBAR_SOURCE ||
-        messageType === messageTypes.TOGGLE_PIN
-      ) {
-        expect(shouldBeInvalidSidebarSource).toBe(true);
-      } else {
-        expect(shouldBeInvalidSidebarSource).toBe(false);
-      }
-    });
+  it('should return false for RawTextMessageInfo', () => {
+    const textMessageInfo: RawTextMessageInfo = {
+      type: messageTypes.TEXT,
+      localID: 'local1',
+      threadID: '10001',
+      creatorID: '123',
+      time: 10000,
+      text: 'This is a text message',
+      id: '1',
+    };
+
+    const shouldBeInvalidSidebarSource =
+      isInvalidSidebarSource(textMessageInfo);
+    expect(shouldBeInvalidSidebarSource).toBe(false);
+  });
+
+  it('should return false for RawCreateThreadMessageInfo', () => {
+    const createThreadMessageInfo: RawCreateThreadMessageInfo = {
+      type: 1,
+      threadID: '10001',
+      creatorID: '123',
+      time: 10000,
+      initialThreadState: {
+        type: threadTypes.COMMUNITY_ROOT,
+        name: 'Random Thread',
+        parentThreadID: '10000',
+        color: '#FFFFFF',
+        memberIDs: ['1', '2', '3'],
+      },
+      id: '1',
+    };
+
+    const shouldBeInvalidSidebarSource = isInvalidSidebarSource(
+      createThreadMessageInfo,
+    );
+    expect(shouldBeInvalidSidebarSource).toBe(false);
+  });
+
+  it('should return false for RawAddMembersMessageInfo', () => {
+    const addMembersMessageInfo: RawAddMembersMessageInfo = {
+      type: messageTypes.ADD_MEMBERS,
+      threadID: '10001',
+      creatorID: '123',
+      time: 10000,
+      addedUserIDs: ['4', '5'],
+      id: '1',
+    };
+
+    const shouldBeInvalidSidebarSource = isInvalidSidebarSource(
+      addMembersMessageInfo,
+    );
+    expect(shouldBeInvalidSidebarSource).toBe(false);
+  });
+
+  it('should return false for RawCreateSubthreadMessageInfo', () => {
+    const createSubthreadMessageInfo: RawCreateSubthreadMessageInfo = {
+      type: messageTypes.CREATE_SUB_THREAD,
+      threadID: '10001',
+      creatorID: '123',
+      time: 10000,
+      childThreadID: '10002',
+      id: '1',
+    };
+
+    const shouldBeInvalidSidebarSource = isInvalidSidebarSource(
+      createSubthreadMessageInfo,
+    );
+    expect(shouldBeInvalidSidebarSource).toBe(false);
+  });
+
+  it('should return false for RawChangeSettingsMessageInfo', () => {
+    const changeSettingsMessageInfo: RawChangeSettingsMessageInfo = {
+      type: messageTypes.CHANGE_SETTINGS,
+      threadID: '10000',
+      creatorID: '123',
+      time: 10000,
+      field: 'color',
+      value: '#FFFFFF',
+      id: '1',
+    };
+
+    const shouldBeInvalidSidebarSource = isInvalidSidebarSource(
+      changeSettingsMessageInfo,
+    );
+    expect(shouldBeInvalidSidebarSource).toBe(false);
+  });
+
+  it('should return false for RawRemoveMembersMessageInfo', () => {
+    const removeMembersMessageInfo: RawRemoveMembersMessageInfo = {
+      type: messageTypes.REMOVE_MEMBERS,
+      threadID: '10000',
+      creatorID: '123',
+      time: 10000,
+      removedUserIDs: ['1', '2', '3'],
+      id: '1',
+    };
+
+    const shouldBeInvalidSidebarSource = isInvalidSidebarSource(
+      removeMembersMessageInfo,
+    );
+    expect(shouldBeInvalidSidebarSource).toBe(false);
+  });
+
+  it('should return false for RawChangeRoleMessageInfo', () => {
+    const changeRoleMessageinfo: RawChangeRoleMessageInfo = {
+      type: messageTypes.CHANGE_ROLE,
+      threadID: '10000',
+      creatorID: '123',
+      time: 10000,
+      userIDs: ['1', '2', '3'],
+      newRole: '101',
+      roleName: 'Moderators',
+      id: '1',
+    };
+
+    const shouldBeInvalidSidebarSource = isInvalidSidebarSource(
+      changeRoleMessageinfo,
+    );
+    expect(shouldBeInvalidSidebarSource).toBe(false);
+  });
+
+  it('should return false for RawLeaveThreadMessageInfo', () => {
+    const leaveThreadMessageInfo: RawLeaveThreadMessageInfo = {
+      type: messageTypes.LEAVE_THREAD,
+      threadID: '10000',
+      creatorID: '123',
+      time: 10000,
+      id: '1',
+    };
+
+    const shouldBeInvalidSidebarSource = isInvalidSidebarSource(
+      leaveThreadMessageInfo,
+    );
+    expect(shouldBeInvalidSidebarSource).toBe(false);
+  });
+
+  it('should return false for RawJoinThreadMessageInfo', () => {
+    const joinThreadMessageInfo: RawJoinThreadMessageInfo = {
+      type: messageTypes.JOIN_THREAD,
+      threadID: '10000',
+      creatorID: '123',
+      time: 10000,
+      id: '1',
+    };
+
+    const shouldBeInvalidSidebarSource = isInvalidSidebarSource(
+      joinThreadMessageInfo,
+    );
+    expect(shouldBeInvalidSidebarSource).toBe(false);
+  });
+
+  it('should return false for RawCreateEntryMessageInfo', () => {
+    const createEntryMessageInfo: RawCreateEntryMessageInfo = {
+      type: messageTypes.CREATE_ENTRY,
+      threadID: '10000',
+      creatorID: '123',
+      time: 10000,
+      entryID: '001',
+      date: '2018-01-01',
+      text: 'This is a calendar entry',
+      id: '1',
+    };
+
+    const shouldBeInvalidSidebarSource = isInvalidSidebarSource(
+      createEntryMessageInfo,
+    );
+    expect(shouldBeInvalidSidebarSource).toBe(false);
+  });
+
+  it('should return false for RawEditEntryMessageInfo', () => {
+    const editEntryMessageInfo: RawEditEntryMessageInfo = {
+      type: messageTypes.EDIT_ENTRY,
+      threadID: '10000',
+      creatorID: '123',
+      time: 10000,
+      entryID: '001',
+      date: '2018-01-01',
+      text: 'This is an edited calendar entry',
+      id: '1',
+    };
+
+    const shouldBeInvalidSidebarSource =
+      isInvalidSidebarSource(editEntryMessageInfo);
+    expect(shouldBeInvalidSidebarSource).toBe(false);
+  });
+
+  it('should return false for RawDeleteEntryMessageInfo', () => {
+    const deleteEntryMessageInfo: RawDeleteEntryMessageInfo = {
+      type: messageTypes.DELETE_ENTRY,
+      threadID: '10000',
+      creatorID: '123',
+      time: 10000,
+      entryID: '001',
+      date: '2018-01-01',
+      text: 'This is a deleted calendar entry',
+      id: '1',
+    };
+
+    const shouldBeInvalidSidebarSource = isInvalidSidebarSource(
+      deleteEntryMessageInfo,
+    );
+    expect(shouldBeInvalidSidebarSource).toBe(false);
+  });
+
+  it('should return false for RawRestoreEntryMessageInfo', () => {
+    const restoreEntryMessageInfo: RawRestoreEntryMessageInfo = {
+      type: messageTypes.RESTORE_ENTRY,
+      threadID: '10000',
+      creatorID: '123',
+      time: 10000,
+      entryID: '001',
+      date: '2018-01-01',
+      text: 'This is a restored calendar entry',
+      id: '1',
+    };
+
+    const shouldBeInvalidSidebarSource = isInvalidSidebarSource(
+      restoreEntryMessageInfo,
+    );
+    expect(shouldBeInvalidSidebarSource).toBe(false);
+  });
+
+  it('should return false for RawUpdateRelationshipMessageInfo', () => {
+    const updateRelationshipMessageInfo: RawUpdateRelationshipMessageInfo = {
+      type: messageTypes.UPDATE_RELATIONSHIP,
+      threadID: '10000',
+      creatorID: '123',
+      targetID: '456',
+      time: 10000,
+      operation: 'request_sent',
+      id: '1',
+    };
+
+    const shouldBeInvalidSidebarSource = isInvalidSidebarSource(
+      updateRelationshipMessageInfo,
+    );
+    expect(shouldBeInvalidSidebarSource).toBe(false);
+  });
+
+  it('should return false for RawImagesMessageInfo', () => {
+    const imageMessageInfo: RawImagesMessageInfo = {
+      type: messageTypes.IMAGES,
+      localID: 'local1',
+      threadID: '10001',
+      creatorID: '123',
+      time: 10000,
+      media: [
+        {
+          id: '1',
+          uri: 'https://example.com/image1.jpg',
+          type: 'photo',
+          dimensions: {
+            height: 100,
+            width: 100,
+          },
+          thumbHash: '1234567890',
+        },
+      ],
+      id: '1',
+    };
+
+    const shouldBeInvalidSidebarSource =
+      isInvalidSidebarSource(imageMessageInfo);
+    expect(shouldBeInvalidSidebarSource).toBe(false);
+  });
+
+  it('should return false for RawMediaMessageInfo', () => {
+    const mediaMessageInfo: RawMediaMessageInfo = {
+      type: messageTypes.MULTIMEDIA,
+      localID: 'local1',
+      threadID: '10001',
+      creatorID: '123',
+      time: 10000,
+      media: [
+        {
+          id: '1',
+          uri: 'https://example.com/image1.jpg',
+          type: 'photo',
+          dimensions: {
+            height: 100,
+            width: 100,
+          },
+          thumbHash: '1234567890',
+        },
+      ],
+      id: '1',
+    };
+
+    const shouldBeInvalidSidebarSource =
+      isInvalidSidebarSource(mediaMessageInfo);
+    expect(shouldBeInvalidSidebarSource).toBe(false);
+  });
+
+  it('should return true for RawSidebarSourceMessageInfo', () => {
+    const sidebarSourceMessageInfo: RawSidebarSourceMessageInfo = {
+      type: messageTypes.SIDEBAR_SOURCE,
+      threadID: '10000',
+      creatorID: '123',
+      time: 10000,
+      sourceMessage: {
+        type: messageTypes.TEXT,
+        localID: 'local1',
+        threadID: '10001',
+        creatorID: '123',
+        time: 10000,
+        text: 'This is a text message',
+        id: '1',
+      },
+      id: '1',
+    };
+
+    const shouldBeInvalidSidebarSource = isInvalidSidebarSource(
+      sidebarSourceMessageInfo,
+    );
+    expect(shouldBeInvalidSidebarSource).toBe(true);
+  });
+
+  it('should return false for RawCreateSidebarMessageInfo', () => {
+    const createSidebarMessageInfo: RawCreateSidebarMessageInfo = {
+      type: messageTypes.CREATE_SIDEBAR,
+      threadID: '10000',
+      creatorID: '123',
+      time: 10000,
+      sourceMessageAuthorID: '123',
+      initialThreadState: {
+        name: 'Random Thread',
+        parentThreadID: '10000',
+        color: '#FFFFFF',
+        memberIDs: ['1', '2', '3'],
+      },
+      id: '1',
+    };
+
+    const shouldBeInvalidSidebarSource = isInvalidSidebarSource(
+      createSidebarMessageInfo,
+    );
+    expect(shouldBeInvalidSidebarSource).toBe(false);
+  });
+
+  it('should return true for RawReactionMessageInfo', () => {
+    const reactionMessageInfo: RawReactionMessageInfo = {
+      type: messageTypes.REACTION,
+      localID: 'local1',
+      threadID: '10001',
+      creatorID: '123',
+      time: 10000,
+      targetMessageID: '1',
+      reaction: 'like',
+      action: 'add_reaction',
+      id: '1',
+    };
+
+    const shouldBeInvalidSidebarSource =
+      isInvalidSidebarSource(reactionMessageInfo);
+    expect(shouldBeInvalidSidebarSource).toBe(true);
+  });
+
+  it('should return true for RawEditMessageInfo', () => {
+    const editMessageInfo: RawEditMessageInfo = {
+      type: messageTypes.EDIT_MESSAGE,
+      threadID: '10000',
+      creatorID: '123',
+      time: 10000,
+      targetMessageID: '1',
+      text: 'This is an edited message',
+      id: '1',
+    };
+
+    const shouldBeInvalidSidebarSource =
+      isInvalidSidebarSource(editMessageInfo);
+    expect(shouldBeInvalidSidebarSource).toBe(true);
+  });
+
+  it('should return true for RawTogglePinMessageInfo', () => {
+    const togglePinMessageInfo: RawTogglePinMessageInfo = {
+      type: messageTypes.TOGGLE_PIN,
+      threadID: '10000',
+      targetMessageID: '1',
+      action: 'pin',
+      pinnedContent: 'a message',
+      creatorID: '123',
+      time: 10000,
+      id: '1',
+    };
+
+    const shouldBeInvalidSidebarSource =
+      isInvalidSidebarSource(togglePinMessageInfo);
+    expect(shouldBeInvalidSidebarSource).toBe(true);
   });
 });
diff --git a/lib/shared/messages/sidebar-source-message-spec.js b/lib/shared/messages/sidebar-source-message-spec.js
--- a/lib/shared/messages/sidebar-source-message-spec.js
+++ b/lib/shared/messages/sidebar-source-message-spec.js
@@ -15,12 +15,12 @@
   type SidebarSourceMessageData,
   type SidebarSourceMessageInfo,
   type ClientDBMessageInfo,
-  isMessageSidebarSourceReactionEditOrPin,
   rawSidebarSourceMessageInfoValidator,
 } from '../../types/message-types.js';
 import type { RawUnsupportedMessageInfo } from '../../types/messages/unsupported.js';
 import type { NotifTexts } from '../../types/notif-types.js';
 import type { RelativeUserInfo } from '../../types/user-types.js';
+import { isInvalidSidebarSource } from '../message-utils.js';
 
 export const sidebarSourceMessageSpec: MessageSpec<
   SidebarSourceMessageData,
@@ -106,7 +106,7 @@
       rawMessageInfo.sourceMessage,
     );
     invariant(
-      sourceMessage && !isMessageSidebarSourceReactionEditOrPin(sourceMessage),
+      sourceMessage && !isInvalidSidebarSource(sourceMessage),
       'Sidebars can not be created from SIDEBAR SOURCE, REACTION, EDIT OR PIN MESSAGE',
     );
 
diff --git a/lib/shared/thread-utils.js b/lib/shared/thread-utils.js
--- a/lib/shared/thread-utils.js
+++ b/lib/shared/thread-utils.js
@@ -1265,7 +1265,7 @@
   if (
     !messageInfo.id ||
     threadInfo.sourceMessageID === messageInfo.id ||
-    isInvalidSidebarSource(messageInfo.type)
+    isInvalidSidebarSource(messageInfo)
   ) {
     return false;
   }
diff --git a/lib/types/message-types.js b/lib/types/message-types.js
--- a/lib/types/message-types.js
+++ b/lib/types/message-types.js
@@ -181,17 +181,6 @@
   return messageData.localID;
 }
 
-export function isMessageSidebarSourceReactionEditOrPin(
-  message: RawMessageInfo | MessageInfo,
-): boolean %checks {
-  return (
-    message.type === messageTypes.SIDEBAR_SOURCE ||
-    message.type === messageTypes.REACTION ||
-    message.type === messageTypes.EDIT_MESSAGE ||
-    message.type === messageTypes.TOGGLE_PIN
-  );
-}
-
 const mediaMessageTypes = new Set([
   messageTypes.IMAGES,
   messageTypes.MULTIMEDIA,