diff --git a/ts/quill/mentions/completion.tsx b/ts/quill/mentions/completion.tsx
index c5e735cb8..a0c5e32c5 100644
--- a/ts/quill/mentions/completion.tsx
+++ b/ts/quill/mentions/completion.tsx
@@ -29,7 +29,7 @@ export type MentionCompletionOptions = {
   theme: ThemeType;
 };
 
-const MENTION_REGEX = /(?:^|\W)@([-+\w]*)$/;
+const MENTION_REGEX = /(?:^|\W)@([-+\p{L}\p{M}\p{N}]+)$/u;
 
 export class MentionCompletion {
   results: ReadonlyArray<ConversationType>;
diff --git a/ts/test-electron/quill/mentions/completion_test.tsx b/ts/test-electron/quill/mentions/completion_test.tsx
index a73f435ed..162719549 100644
--- a/ts/test-electron/quill/mentions/completion_test.tsx
+++ b/ts/test-electron/quill/mentions/completion_test.tsx
@@ -28,7 +28,6 @@ const me: ConversationType = getDefaultConversationWithUuid({
   isMe: true,
 });
 
-// TODO diacritic
 const members: Array<ConversationType> = [
   getDefaultConversationWithUuid({
     id: '555444',