diff --git a/implementations/javascript/packages/core/src/dictionary.ts b/implementations/javascript/packages/core/src/dictionary.ts
index a2db039..570614b 100644
--- a/implementations/javascript/packages/core/src/dictionary.ts
+++ b/implementations/javascript/packages/core/src/dictionary.ts
@@ -1,17 +1,17 @@
-import { Encoder, canonicalEncode, canonicalString } from "./encoder";
+import { Encodable, Encoder, canonicalEncode, canonicalString } from "./encoder";
 import { Tag } from "./constants";
 import { FlexMap, FlexSet, _iterMap } from "./flex";
 import { Value } from "./values";
 import { Bytes } from './bytes';
 import { GenericEmbedded } from "./embedded";
 import type { Preservable } from "./encoder";
-import type { Writer, PreserveWritable } from "./writer";
+import type { Writable, Writer, PreserveWritable } from "./writer";
 import { annotations, Annotated } from "./annotated";
 
 export type DictionaryType = 'Dictionary' | 'Set';
 export const DictionaryType = Symbol.for('DictionaryType');
 
-export class KeyedDictionary<K extends Value<T>, V, T = GenericEmbedded> extends FlexMap<K, V>
+export class KeyedDictionary<K extends (Encodable<T> & Writable<T>), V, T = GenericEmbedded> extends FlexMap<K, V>
     implements Preservable<T>, PreserveWritable<T>
 {
     get [DictionaryType](): DictionaryType {