diff --git a/src/components/autocomplete/autocomplete.jsx b/src/components/autocomplete/autocomplete.jsx
index ad6ccac96..285a08e7b 100644
--- a/src/components/autocomplete/autocomplete.jsx
+++ b/src/components/autocomplete/autocomplete.jsx
@@ -7,7 +7,7 @@ import { Selector } from './selector';
 
 // There should be no alphanumeric characters right before the "@" (to exclude
 // email-like strings)
-const defaultAnchor = /(?<![a-z\d])@/gi;
+const defaultAnchor = /(^|[^a-z\d])@/gi;
 
 export function Autocomplete({ inputRef, context, anchor = defaultAnchor }) {
   const [query, setQuery] = useState(/** @type {string|null}*/ null);
diff --git a/src/components/layout-header.jsx b/src/components/layout-header.jsx
index 9c3dfa6f5..22b012e50 100644
--- a/src/components/layout-header.jsx
+++ b/src/components/layout-header.jsx
@@ -13,7 +13,7 @@ import styles from './layout-header.module.scss';
 import { SignInLink } from './sign-in-link';
 import { Autocomplete } from './autocomplete/autocomplete';
 
-const autocompleteAnchor = /(?<![a-z\d])@|((from|to|author|by|in|commented-?by|liked-?by):)/gi;
+const autocompleteAnchor = /(^|[^a-z\d])@|((from|to|author|by|in|commented-?by|liked-?by):)/gi;
 
 export const LayoutHeader = withRouter(function LayoutHeader({ router }) {
   const dispatch = useDispatch();