diff --git a/types/nedb/index.d.ts b/types/nedb/index.d.ts
index e336aa8ab4..c13b7efb5b 100644
--- a/types/nedb/index.d.ts
+++ b/types/nedb/index.d.ts
@@ -4,6 +4,7 @@
 //                 Anthony Nichols <https://github.com/anthonynichols>
 //                 Alejandro Fernandez Haro <https://github.com/afharo>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.3
 
 /// <reference types="node" />
 
@@ -12,7 +13,7 @@ import { EventEmitter } from 'events';
 export = Nedb;
 export as namespace Nedb;
 
-declare class Nedb extends EventEmitter {
+declare class Nedb<G = any> extends EventEmitter {
     constructor(pathOrOptions?: string | Nedb.DataStoreOptions);
 
     persistence: Nedb.Persistence;
@@ -49,20 +50,20 @@ declare class Nedb extends EventEmitter {
     /**
      * Add one or several document(s) to all indexes
      */
-    addToIndexes<T>(doc: T | T[]): void;
+    addToIndexes<T extends G>(doc: T | T[]): void;
 
     /**
      * Remove one or several document(s) from all indexes
      */
-    removeFromIndexes<T>(doc: T | T[]): void;
+    removeFromIndexes<T extends G>(doc: T | T[]): void;
 
     /**
      * Update one or several documents in all indexes
      * To update multiple documents, oldDoc must be an array of { oldDoc, newDoc } pairs
      * If one update violates a constraint, all changes are rolled back
      */
-    updateIndexes<T>(oldDoc: T, newDoc: T): void;
-    updateIndexes<T>(updates: Array<{ oldDoc: T; newDoc: T }>): void;
+    updateIndexes<T extends G>(oldDoc: T, newDoc: T): void;
+    updateIndexes<T extends G>(updates: Array<{ oldDoc: T; newDoc: T }>): void;
 
     /**
      * Return the list of candidates for a given query
@@ -79,7 +80,7 @@ declare class Nedb extends EventEmitter {
      * Insert a new document
      * @param cb Optional callback, signature: err, insertedDoc
      */
-    insert<T>(newDoc: T, cb?: (err: Error, document: T) => void): void;
+    insert<T extends G>(newDoc: T, cb?: (err: Error, document: T) => void): void;
 
     /**
      * Count all documents matching the query
@@ -94,28 +95,28 @@ declare class Nedb extends EventEmitter {
      * @param query MongoDB-style query
      * @param projection MongoDB-style projection
      */
-    find<T>(query: any, projection: T, callback: (err: Error, documents: T[]) => void): void;
-    find<T>(query: any, projection?: T): Nedb.Cursor<T>;
+    find<T extends G>(query: any, projection: T, callback: (err: Error, documents: T[]) => void): void;
+    find<T extends G>(query: any, projection?: T): Nedb.Cursor<T>;
 
     /**
      * Find all documents matching the query
      * If no callback is passed, we return the cursor so that user can limit, skip and finally exec
      * * @param {any} query MongoDB-style query
      */
-    find<T>(query: any, callback: (err: Error, documents: T[]) => void): void;
+    find<T extends G>(query: any, callback: (err: Error, documents: T[]) => void): void;
 
     /**
      * Find one document matching the query
      * @param query MongoDB-style query
      * @param projection MongoDB-style projection
      */
-    findOne<T>(query: any, projection: T, callback: (err: Error, document: T) => void): void;
+    findOne<T extends G>(query: any, projection: T, callback: (err: Error, document: T) => void): void;
 
     /**
      * Find one document matching the query
      * @param query MongoDB-style query
      */
-    findOne<T>(query: any, callback: (err: Error, document: T) => void): void;
+    findOne<T extends G>(query: any, callback: (err: Error, document: T) => void): void;
 
     /**
      * Update all docs matching query v1.7.4 and prior signature.
@@ -144,7 +145,7 @@ declare class Nedb extends EventEmitter {
      *
      * @api private Use Datastore.update which has the same signature
      */
-    update<T>(query: any, updateQuery: any, options?: Nedb.UpdateOptions, cb?: (err: Error, numberOfUpdated: number, affectedDocuments: any, upsert: boolean) => void): void;
+    update<T extends G>(query: any, updateQuery: any, options?: Nedb.UpdateOptions, cb?: (err: Error, numberOfUpdated: number, affectedDocuments: any, upsert: boolean) => void): void;
 
     /**
      * Remove all docs matching the query