@@ -57,7 +57,6 @@ Technically any value can be used.
  * @property {number} length
  * @property {number} cycleStackSize
  * @property {number} referenceableSize
- * @property {number} overwrittenReferencesLength
  * @property {number} currentPos
  * @property {number} objectTypeLookupSize
  * @property {number} currentPosTypeLookup
@@ -375,22 +374,11 @@ class ObjectMiddleware extends SerializerMiddleware {
 		let currentPos = 0;
 		/** @type {Map<ReferenceableItem, number>} */
 		let referenceable = new Map();
-		/**
-		 * Item and prior position, in pairs, for the positions `addReferenceable` replaced.
-		 * @type {(ReferenceableItem | number)[]}
-		 */
-		const overwrittenReferences = [];
 		/**
 		 * Adds referenceable.
 		 * @param {ReferenceableItem} item referenceable item
 		 */
 		const addReferenceable = (item) => {
-			const previous = referenceable.get(item);
-			// `setMapSize` can only drop keys added since a snapshot, so an
-			// overwritten position has to be recorded to be undone
-			if (previous !== undefined) {
-				overwrittenReferences.push(item, previous);
-			}
 			referenceable.set(item, currentPos++);
 		};
 		/** @type {Map<number, Buffer | [Buffer, Buffer] | Map<string, Buffer>>} */
@@ -747,7 +735,6 @@ class ObjectMiddleware extends SerializerMiddleware {
 					length: result.length,
 					cycleStackSize: cycleStack.length,
 					referenceableSize: referenceable.size,
-					overwrittenReferencesLength: overwrittenReferences.length,
 					currentPos,
 					objectTypeLookupSize: objectTypeLookup.size,
 					currentPosTypeLookup
@@ -756,19 +743,15 @@ class ObjectMiddleware extends SerializerMiddleware {
 			rollback(snapshot) {
 				result.length = snapshot.length;
 				cycleStack.length = snapshot.cycleStackSize;
-				// newest first, so the oldest recorded position is the one kept,
-				// and before the truncation that drops the keys added since
-				for (
-					let i = overwrittenReferences.length - 2;
-					i >= snapshot.overwrittenReferencesLength;
-					i -= 2
-				) {
-					referenceable.set(
-						/** @type {ReferenceableItem} */ (overwrittenReferences[i]),
-						/** @type {number} */ (overwrittenReferences[i + 1])
-					);
+				// a `setCircularReference` since the snapshot replaced a marker on an
+				// item already keyed here, which `setMapSize` cannot undo
+				for (let i = 0; i < cycleStack.length; i++) {
+					const item = /** @type {ReferenceableItem} */ (cycleStack[i]);
+					const ref = referenceable.get(item);
+					if (ref !== undefined && ref >= snapshot.currentPos) {
+						referenceable.set(item, IN_PROGRESS);
+					}
 				}
-				overwrittenReferences.length = snapshot.overwrittenReferencesLength;
 				setMapSize(referenceable, snapshot.referenceableSize);
 				currentPos = snapshot.currentPos;
 				setMapSize(objectTypeLookup, snapshot.objectTypeLookupSize);
 
@@ -20030,7 +20030,6 @@ declare interface ObjectSerializerSnapshot {
 	length: number;
 	cycleStackSize: number;
 	referenceableSize: number;
-	overwrittenReferencesLength: number;
 	currentPos: number;
 	objectTypeLookupSize: number;
 	currentPosTypeLookup: number;