diff --git a/packages/core/src/runtime/bag.ts b/packages/core/src/runtime/bag.ts
index 0d1a1d9..ba45fc7 100644
--- a/packages/core/src/runtime/bag.ts
+++ b/packages/core/src/runtime/bag.ts
@@ -3,7 +3,7 @@
 
 // Bags and Deltas (which are Bags where item-counts can be negative).
 
-import { Value, Set, Dictionary, KeyedDictionary, KeyedSet } from '@preserves/core';
+import { Value, KeyedDictionary, KeyedSet } from '@preserves/core';
 
 export enum ChangeDescription {
     PRESENT_TO_ABSENT = -1,
diff --git a/packages/core/src/runtime/dataflow.ts b/packages/core/src/runtime/dataflow.ts
index db2447d..b980bb5 100644
--- a/packages/core/src/runtime/dataflow.ts
+++ b/packages/core/src/runtime/dataflow.ts
@@ -3,9 +3,8 @@
 
 // Property-based "dataflow"
 
-import { FlexSet, FlexMap, Canonicalizer, Value, is } from '@preserves/core';
-import { Ref } from './actor.js';
-import * as MapSet from './mapset.js';
+import { FlexSet, FlexMap, Canonicalizer, is } from '@preserves/core';
+import * as MapSet from './mapset';
 
 export interface ObservingGraph<ObjectId> {
     recordObservation(objectId: ObjectId): void;