diff --git a/pylib/anki/collection.py b/pylib/anki/collection.py
index d6d2525f3..87cb80d43 100644
--- a/pylib/anki/collection.py
+++ b/pylib/anki/collection.py
@@ -784,11 +784,5 @@ table.review-log {{ {revlog_style} }}
         )
 
 
-def nid_search_term(nids: List[int]) -> SearchTerm:
-    """Helper function for building a NoteIDs message."""
-
-    return SearchTerm(nids=NoteIDs(nids=nids))
-
-
 # legacy name
 _Collection = Collection
diff --git a/qt/aqt/addcards.py b/qt/aqt/addcards.py
index 7de8b3f24..121ff145e 100644
--- a/qt/aqt/addcards.py
+++ b/qt/aqt/addcards.py
@@ -7,7 +7,7 @@ import aqt.deckchooser
 import aqt.editor
 import aqt.forms
 import aqt.modelchooser
-from anki.collection import nid_search_term
+from anki.backend_pb2 import SearchTerm
 from anki.consts import MODEL_CLOZE
 from anki.notes import Note
 from anki.utils import htmlToTextLine, isMac
@@ -145,7 +145,7 @@ class AddCards(QDialog):
     def onHistory(self) -> None:
         m = QMenu(self)
         for nid in self.history:
-            if self.mw.col.findNotes(nid_search_term([nid])):
+            if self.mw.col.findNotes(SearchTerm(nid=nid)):
                 note = self.mw.col.getNote(nid)
                 fields = note.fields
                 txt = htmlToTextLine(", ".join(fields))
@@ -162,7 +162,7 @@ class AddCards(QDialog):
         m.exec_(self.historyButton.mapToGlobal(QPoint(0, 0)))
 
     def editHistory(self, nid):
-        self.mw.browser_search(nid_search_term([nid]))
+        self.mw.browser_search(SearchTerm(nid=nid))
 
     def addNote(self, note) -> Optional[Note]:
         note.model()["did"] = self.deckChooser.selectedId()
diff --git a/qt/aqt/browser.py b/qt/aqt/browser.py
index b4cd6f202..77bf9def9 100644
--- a/qt/aqt/browser.py
+++ b/qt/aqt/browser.py
@@ -13,7 +13,7 @@ from typing import List, Optional, Sequence, Tuple, cast
 import aqt
 import aqt.forms
 from anki.cards import Card
-from anki.collection import Collection, InvalidInput, SearchTerm, nid_search_term
+from anki.collection import Collection, InvalidInput, SearchTerm
 from anki.consts import *
 from anki.lang import without_unicode_isolation
 from anki.models import NoteType
@@ -681,7 +681,7 @@ class Browser(QMainWindow):
         nid = card and card.nid
         if nid:
             self.card = card
-            search = self.col.build_search_string(nid_search_term([nid]))
+            search = self.col.build_search_string(SearchTerm(nid=nid))
             search = gui_hooks.default_search(search, card)
             self.form.searchEdit.lineEdit().setText(search)
             self.onSearchActivated()
@@ -1522,7 +1522,9 @@ where id in %s"""
         tv = self.form.tableView
         tv.selectionModel().clear()
 
-        search = self.col.build_search_string(nid_search_term(nids))
+        search = self.col.build_search_string(
+            SearchTerm(nids=SearchTerm.IdList(ids=nids))
+        )
         self.search_for(search)
 
         tv.selectAll()
@@ -1731,7 +1733,11 @@ where id in %s"""
             t += (
                 """<li><a href=# onclick="pycmd('%s');return false;">%s</a>: %s</a>"""
                 % (
-                    html.escape(self.col.build_search_string(nid_search_term(nids))),
+                    html.escape(
+                        self.col.build_search_string(
+                            SearchTerm(nids=SearchTerm.IdList(ids=nids))
+                        )
+                    ),
                     tr(TR.BROWSING_NOTE_COUNT, count=len(nids)),
                     html.escape(val),
                 )
diff --git a/qt/aqt/mediacheck.py b/qt/aqt/mediacheck.py
index 3b128975d..d6129e5ce 100644
--- a/qt/aqt/mediacheck.py
+++ b/qt/aqt/mediacheck.py
@@ -9,7 +9,7 @@ from concurrent.futures import Future
 from typing import Iterable, List, Optional, Sequence, TypeVar
 
 import aqt
-from anki.collection import nid_search_term
+from anki.backend_pb2 import SearchTerm
 from anki.rsbackend import TR, Interrupted, ProgressKind, pb
 from aqt.qt import *
 from aqt.utils import (
@@ -146,7 +146,7 @@ class MediaChecker:
 
         if out is not None:
             nid, err = out
-            self.mw.browser_search(nid_search_term([nid]))
+            self.mw.browser_search(SearchTerm(nid=nid))
             showText(err, type="html")
         else:
             tooltip(tr(TR.MEDIA_CHECK_ALL_LATEX_RENDERED))
diff --git a/rslib/backend.proto b/rslib/backend.proto
index 70d8a9269..238a71de6 100644
--- a/rslib/backend.proto
+++ b/rslib/backend.proto
@@ -797,12 +797,15 @@ message SearchTerm {
     SUSPENDED = 4;
     BURIED = 5;
   }
+  message IdList {
+    repeated int64 ids = 1;
+  }
   oneof filter {
     string tag = 1;
     string deck = 2;
     string note = 3;
     uint32 template = 4;
-    NoteIDs nids = 5;
+    int64 nid = 5;
     Dupe dupe = 6;
     string field_name = 7;
     Rated rated = 8;
@@ -812,6 +815,7 @@ message SearchTerm {
     bool current_deck = 12;
     Flag flag = 13;
     CardState card_state = 14;
+    IdList nids = 15;
   }
 }
 
diff --git a/rslib/src/backend/mod.rs b/rslib/src/backend/mod.rs
index 4936e0554..52e0e6be9 100644
--- a/rslib/src/backend/mod.rs
+++ b/rslib/src/backend/mod.rs
@@ -262,9 +262,9 @@ impl From<pb::NoteId> for NoteID {
     }
 }
 
-impl pb::NoteIDs {
+impl pb::search_term::IdList {
     fn into_id_string(self) -> String {
-        self.nids
+        self.ids
             .iter()
             .map(|i| i.to_string())
             .collect::<Vec<_>>()
@@ -307,6 +307,7 @@ impl From<pb::SearchTerm> for Node<'_> {
             Filter::Template(u) => {
                 Node::Search(SearchNode::CardTemplate(TemplateKind::Ordinal(u as u16)))
             }
+            Filter::Nid(nid) => Node::Search(SearchNode::NoteIDs(nid.to_string().into())),
             Filter::Nids(nids) => Node::Search(SearchNode::NoteIDs(nids.into_id_string().into())),
             Filter::Dupe(dupe) => Node::Search(SearchNode::Duplicates {
                 note_type_id: dupe.notetype_id.into(),