diff --git a/fs-extra/fs-extra-tests.ts b/fs-extra/fs-extra-tests.ts
index 80655ab5b8..32fc34d76d 100644
--- a/fs-extra/fs-extra-tests.ts
+++ b/fs-extra/fs-extra-tests.ts
@@ -75,10 +75,10 @@ fs.outputJSON(file, data, errorCallback);
 fs.outputJsonSync(file, data);
 fs.outputJSONSync(file, data);
 
-fs.readJson(file, errorCallback);
-fs.readJson(file, openOpts, errorCallback);
-fs.readJSON(file, errorCallback);
-fs.readJSON(file, openOpts, errorCallback);
+fs.readJson(file, (error: Error, jsonObject: any) => {});
+fs.readJson(file, openOpts, (error: Error, jsonObject: any) => {});
+fs.readJSON(file, (error: Error, jsonObject: any) => {});
+fs.readJSON(file, openOpts, (error: Error, jsonObject: any) => {});
 
 fs.readJsonSync(file, openOpts);
 fs.readJSONSync(file, openOpts);
diff --git a/fs-extra/fs-extra.d.ts b/fs-extra/fs-extra.d.ts
index e4f800185f..b5cba7c083 100644
--- a/fs-extra/fs-extra.d.ts
+++ b/fs-extra/fs-extra.d.ts
@@ -65,10 +65,10 @@ declare module "fs-extra" {
 	export function outputJsonSync(file: string, data: any): void;
 	export function outputJSONSync(file: string, data: any): void;
 
-	export function readJson(file: string, callback?: (err: Error) => void): void;
-	export function readJson(file: string, options?: OpenOptions, callback?: (err: Error) => void): void;
-	export function readJSON(file: string, callback?: (err: Error) => void): void;
-	export function readJSON(file: string, options?: OpenOptions, callback?: (err: Error) => void): void;
+	export function readJson(file: string, callback: (err: Error, jsonObject: any) => void): void;
+	export function readJson(file: string, options: OpenOptions, callback: (err: Error, jsonObject: any) => void): void;
+	export function readJSON(file: string, callback: (err: Error, jsonObject: any) => void): void;
+	export function readJSON(file: string, options: OpenOptions, callback: (err: Error, jsonObject: any) => void): void;
 
 	export function readJsonSync(file: string, options?: OpenOptions): any;
 	export function readJSONSync(file: string, options?: OpenOptions): any;