diff --git a/CHANGELOG.md b/CHANGELOG.md
index ffc664fce..75040a967 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,8 @@
 
 ## [Unreleased]
 
+- fix: add `bigint` to the `JsonValue` types in `@dfinity/candid`.
+
 ## [3.2.1] - 2025-08-12
 
 - fix: export the `GenericIdlFuncArgs`, `GenericIdlFuncRets`, and `GenericIdlServiceFields` types from `@dfinity/candid`.
diff --git a/packages/candid/src/types.ts b/packages/candid/src/types.ts
index 540032366..e8015690a 100644
--- a/packages/candid/src/types.ts
+++ b/packages/candid/src/types.ts
@@ -4,4 +4,4 @@ export interface JsonArray extends Array<JsonValue> {}
 
 export interface JsonObject extends Record<string, JsonValue> {}
 
-export type JsonValue = boolean | string | number | JsonArray | JsonObject;
+export type JsonValue = boolean | string | number | bigint | JsonArray | JsonObject;