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
@@ -105,7 +105,7 @@
 import { useSelector } from '../utils/redux-utils.js';
 import { firstLine } from '../utils/string-utils.js';
 import { trimText } from '../utils/text-utils.js';
-import { idSchemaRegex } from '../utils/validation-utils.js';
+import { pendingThreadIDRegex } from '../utils/validation-utils.js';
 
 const chatNameMaxLength = 191;
 const chatNameMinLength = 0;
@@ -277,8 +277,6 @@
   return `pending/${pendingThreadTypeString}${pendingThreadKey}`;
 }
 
-const pendingThreadIDRegex = `pending/(type[0-9]+/[0-9]+(\\+[0-9]+)*|sidebar/${idSchemaRegex})`;
-
 type PendingThreadIDContents = {
   +threadType: ThreadType,
   +memberIDs: $ReadOnlyArray<string>,
@@ -1792,7 +1790,6 @@
   threadIsPendingSidebar,
   getSingleOtherUser,
   getPendingThreadID,
-  pendingThreadIDRegex,
   parsePendingThreadID,
   createPendingThread,
   createUnresolvedPendingSidebar,
diff --git a/lib/utils/url-utils.js b/lib/utils/url-utils.js
--- a/lib/utils/url-utils.js
+++ b/lib/utils/url-utils.js
@@ -2,8 +2,12 @@
 
 import t, { type TInterface } from 'tcomb';
 
-import { idSchemaRegex, tID, tShape } from './validation-utils.js';
-import { pendingThreadIDRegex } from '../shared/thread-utils.js';
+import {
+  idSchemaRegex,
+  tID,
+  tShape,
+  pendingThreadIDRegex,
+} from './validation-utils.js';
 
 export type URLInfo = {
   +year?: number,
diff --git a/lib/utils/validation-utils.js b/lib/utils/validation-utils.js
--- a/lib/utils/validation-utils.js
+++ b/lib/utils/validation-utils.js
@@ -105,6 +105,8 @@
 
 const idSchemaRegex = '(?:[0-9]+\\|)?[0-9]+';
 
+const pendingThreadIDRegex = `pending/(type[0-9]+/[0-9]+(\\+[0-9]+)*|sidebar/${idSchemaRegex})`;
+
 export {
   tBool,
   tString,
@@ -129,4 +131,5 @@
   assertWithValidator,
   ashoatKeyserverID,
   idSchemaRegex,
+  pendingThreadIDRegex,
 };