diff --git a/packages/realm/src/JSONCacheMap.ts b/packages/realm/src/JSONCacheMap.ts
index 6893461601..47f9e95254 100644
--- a/packages/realm/src/JSONCacheMap.ts
+++ b/packages/realm/src/JSONCacheMap.ts
@@ -19,8 +19,8 @@
 import { DefaultObject, INTERNAL, RealmObject } from "./internal";
 
 /** @internal */
-export class JSONCacheMap extends Map<number, Map<string, DefaultObject>> {
-  add<T>(object: RealmObject<T>, value: DefaultObject) {
+export class JSONCacheMap<T = DefaultObject> extends Map<number, Map<string, T>> {
+  add<U>(object: RealmObject<U>, value: T) {
     const tableKey = object[INTERNAL].table.key;
     let cachedMap = this.get(tableKey);
     if (!cachedMap) {
@@ -29,7 +29,7 @@ export class JSONCacheMap extends Map<number, Map<string, DefaultObject>> {
     }
     cachedMap.set(object._objectKey(), value);
   }
-  find<T>(object: RealmObject<T>) {
+  find<U>(object: RealmObject<U>) {
     return this.get(object[INTERNAL].table.key)?.get(object._objectKey());
   }
 }
diff --git a/packages/realm/src/Object.ts b/packages/realm/src/Object.ts
index 4e96620f0e..248dce49b1 100644
--- a/packages/realm/src/Object.ts
+++ b/packages/realm/src/Object.ts
@@ -382,9 +382,9 @@ export class RealmObject<T = DefaultObject, RequiredProperties extends keyof Omi
    * and [flatted](https://www.npmjs.com/package/flatted) to stringify Realm entities that have circular structures.
    * @returns A plain object.
    */
-  toJSON(_?: string, cache?: unknown): DefaultObject;
+  toJSON(_?: string, cache?: unknown): OmittedRealmTypes<T>;
   /** @internal */
-  toJSON(_?: string, cache = new JSONCacheMap()): DefaultObject {
+  toJSON(_?: string, cache = new JSONCacheMap<T>()): OmittedRealmTypes<T> {
     // Construct a reference-id of table-name & primaryKey if it exists, or fall back to objectId.
 
     // Check if current objectId has already processed, to keep object references the same.
@@ -392,7 +392,7 @@ export class RealmObject<T = DefaultObject, RequiredProperties extends keyof Omi
     if (existing) {
       return existing;
     }
-    const result: DefaultObject = {};
+    const result = {} as T;
     cache.add(this, result);
     // Move all enumerable keys to result, triggering any specific toJSON implementation in the process.
     for (const key in this) {