diff --git a/src/app/components/editor/autocomplete/RoomMentionAutocomplete.tsx b/src/app/components/editor/autocomplete/RoomMentionAutocomplete.tsx
index 91fffbab0..2935245ac 100644
--- a/src/app/components/editor/autocomplete/RoomMentionAutocomplete.tsx
+++ b/src/app/components/editor/autocomplete/RoomMentionAutocomplete.tsx
@@ -140,7 +140,8 @@ export function RoomMentionAutocomplete({
   };
 
   useKeyDown(window, (evt: KeyboardEvent) => onTabPress(evt, pickTop));
-  useAutocompleteEnter(true, pickTop);
+  // Same rule as people: a fully typed #alias:server sends as typed.
+  useAutocompleteEnter(!query.text.includes(':'), pickTop);
 
   return (
     <AutocompleteMenu headerContent={<Text size="L400">Rooms</Text>} requestClose={requestClose}>
diff --git a/src/app/components/editor/autocomplete/UserMentionAutocomplete.tsx b/src/app/components/editor/autocomplete/UserMentionAutocomplete.tsx
index 9ab348290..48fbbb070 100644
--- a/src/app/components/editor/autocomplete/UserMentionAutocomplete.tsx
+++ b/src/app/components/editor/autocomplete/UserMentionAutocomplete.tsx
@@ -140,9 +140,9 @@ export function UserMentionAutocomplete({
   };
 
   useKeyDown(window, (evt: KeyboardEvent) => onTabPress(evt, pickTop));
-  // The list always shows a suggestion (a member, or the typed id), so Enter
-  // always picks rather than sending "hey @bo".
-  useAutocompleteEnter(true, pickTop);
+  // Enter picks while a partial name is being typed ("hey @bo"). Once a full
+  // user ID has been typed ("/kick @alice:server"), Enter sends as typed.
+  useAutocompleteEnter(!query.text.includes(':'), pickTop);
 
   const getName = (member: RoomMember) => getMemberName(room, member.userId);