diff --git a/src/pitch.ts b/src/pitch.ts
index 7fde8df5..8282049e 100644
--- a/src/pitch.ts
+++ b/src/pitch.ts
@@ -894,7 +894,9 @@ export class Pitch extends prebase.ProtoM21Object {
                         this.accidental = new Accidental('natural');
                     }
                     this.accidental.displayStatus = true;
-
+                // not exactly equivalent with https://github.com/cuthbertLab/music21/pull/1299
+                // because m21j does not track chordAttached
+                // Thus, some potential for subsequent same pitch class to lack a cautionary natural
                     // other cases: already natural in past usage, do not need
                     // natural again (and not in key sig)
                 } else {
diff --git a/src/stream.ts b/src/stream.ts
index d994da65..c2f0bc0b 100644
--- a/src/stream.ts
+++ b/src/stream.ts
@@ -26,6 +26,7 @@ import { Music21Exception } from './exceptions21';
 import { debug } from './debug';
 
 import * as base from './base';
+import { Chord } from './chord';
 import * as clef from './clef';
 import * as common from './common';
 import * as derivation from './derivation';
@@ -47,7 +48,6 @@ import * as iterator from './stream/iterator';
 import * as makeNotation from './stream/makeNotation';
 
 // for typing only
-import type { Chord } from './chord';
 import type { KeySignature } from './key';
 
 export { filters };
@@ -1815,9 +1815,10 @@ export class Stream extends base.Music21Object {
                 if (tie !== undefined && tie.type !== 'stop') {
                     tiePitchSet.add(p.nameWithOctave);
                 }
-            } else if (e.classes.includes('Chord')) {
-                const chordNotes = (e as Chord).notes;
+            } else if (e instanceof Chord) {
+                const chordNotes = e.notes;
                 const seenPitchNames: Set<string> = new Set();
+                pitchPast.push(...e.pitches);
                 for (const n of chordNotes) {
                     const p = n.pitch;
                     const lastNoteWasTied: boolean = tiePitchSet.has(p.nameWithOctave);
@@ -1841,7 +1842,6 @@ export class Stream extends base.Music21Object {
                 for (const pName of seenPitchNames) {
                     tiePitchSet.add(pName);
                 }
-                pitchPast.push(...(e as Chord).pitches);
             } else {
                 tiePitchSet.clear();
             }
diff --git a/tests/moduleTests/stream.ts b/tests/moduleTests/stream.ts
index 05652d0b..ed455a4f 100644
--- a/tests/moduleTests/stream.ts
+++ b/tests/moduleTests/stream.ts
@@ -554,6 +554,14 @@ export default function tests() {
         assert.ok(n2.pitch.accidental.displayStatus);  // different note
     });
 
+    test('music21.stream.Stream makeAccidentals augmented unison in chord', assert => {
+        const m = new music21.stream.Measure();
+        const c = new music21.chord.Chord('G# G');
+        m.append(c);
+        m.makeAccidentals({inPlace: true});
+        assert.ok(c.pitches[0].accidental.displayStatus);  // G comes first
+    });
+
     test('music21.stream.Stream makeBeams with stemDirection', assert => {
         const n1 = new music21.note.Note('C5', 0.5);
         n1.stemDirection = 'up';