diff --git a/types/node/index.d.ts b/types/node/index.d.ts
index 717b906b28..41831a6a73 100644
--- a/types/node/index.d.ts
+++ b/types/node/index.d.ts
@@ -19,6 +19,7 @@
 //                 Alberto Schiabel <https://github.com/jkomyno>
 //                 Klaus Meinhardt <https://github.com/ajafff>
 //                 Huw <https://github.com/hoo29>
+//                 Nicolas Even <https://github.com/n-e>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 
 /** inspector module types */
@@ -5562,18 +5563,18 @@ declare module "util" {
     export function callbackify<T1, T2, T3, T4, T5, T6, TResult>(fn: (arg1: T1, arg2: T2, arg3: T3, arg4: T4, arg5: T5, arg6: T6) => Promise<TResult>): (arg1: T1, arg2: T2, arg3: T3, arg4: T4, arg5: T5, arg6: T6, callback: (err: NodeJS.ErrnoException, result: TResult) => void) => void;
 
     export function promisify<TCustom extends Function>(fn: CustomPromisify<TCustom>): TCustom;
-    export function promisify<TResult>(fn: (callback: (err: Error, result: TResult) => void) => void): () => Promise<TResult>;
-    export function promisify(fn: (callback: (err: Error) => void) => void): () => Promise<void>;
-    export function promisify<T1, TResult>(fn: (arg1: T1, callback: (err: Error, result: TResult) => void) => void): (arg1: T1) => Promise<TResult>;
-    export function promisify<T1>(fn: (arg1: T1, callback: (err: Error) => void) => void): (arg1: T1) => Promise<void>;
-    export function promisify<T1, T2, TResult>(fn: (arg1: T1, arg2: T2, callback: (err: Error, result: TResult) => void) => void): (arg1: T1, arg2: T2) => Promise<TResult>;
-    export function promisify<T1, T2>(fn: (arg1: T1, arg2: T2, callback: (err: Error) => void) => void): (arg1: T1, arg2: T2) => Promise<void>;
-    export function promisify<T1, T2, T3, TResult>(fn: (arg1: T1, arg2: T2, arg3: T3, callback: (err: Error, result: TResult) => void) => void): (arg1: T1, arg2: T2, arg3: T3) => Promise<TResult>;
-    export function promisify<T1, T2, T3>(fn: (arg1: T1, arg2: T2, arg3: T3, callback: (err: Error) => void) => void): (arg1: T1, arg2: T2, arg3: T3) => Promise<void>;
-    export function promisify<T1, T2, T3, T4, TResult>(fn: (arg1: T1, arg2: T2, arg3: T3, arg4: T4, callback: (err: Error, result: TResult) => void) => void): (arg1: T1, arg2: T2, arg3: T3, arg4: T4) => Promise<TResult>;
-    export function promisify<T1, T2, T3, T4>(fn: (arg1: T1, arg2: T2, arg3: T3, arg4: T4, callback: (err: Error) => void) => void): (arg1: T1, arg2: T2, arg3: T3, arg4: T4) => Promise<void>;
-    export function promisify<T1, T2, T3, T4, T5, TResult>(fn: (arg1: T1, arg2: T2, arg3: T3, arg4: T4, arg5: T5, callback: (err: Error, result: TResult) => void) => void): (arg1: T1, arg2: T2, arg3: T3, arg4: T4, arg5: T5) => Promise<TResult>;
-    export function promisify<T1, T2, T3, T4, T5>(fn: (arg1: T1, arg2: T2, arg3: T3, arg4: T4, arg5: T5, callback: (err: Error) => void) => void): (arg1: T1, arg2: T2, arg3: T3, arg4: T4, arg5: T5) => Promise<void>;
+    export function promisify<TResult>(fn: (callback: (err: Error | null, result: TResult) => void) => void): () => Promise<TResult>;
+    export function promisify(fn: (callback: (err: Error | null) => void) => void): () => Promise<void>;
+    export function promisify<T1, TResult>(fn: (arg1: T1, callback: (err: Error | null, result: TResult) => void) => void): (arg1: T1) => Promise<TResult>;
+    export function promisify<T1>(fn: (arg1: T1, callback: (err: Error | null) => void) => void): (arg1: T1) => Promise<void>;
+    export function promisify<T1, T2, TResult>(fn: (arg1: T1, arg2: T2, callback: (err: Error | null, result: TResult) => void) => void): (arg1: T1, arg2: T2) => Promise<TResult>;
+    export function promisify<T1, T2>(fn: (arg1: T1, arg2: T2, callback: (err: Error | null) => void) => void): (arg1: T1, arg2: T2) => Promise<void>;
+    export function promisify<T1, T2, T3, TResult>(fn: (arg1: T1, arg2: T2, arg3: T3, callback: (err: Error | null, result: TResult) => void) => void): (arg1: T1, arg2: T2, arg3: T3) => Promise<TResult>;
+    export function promisify<T1, T2, T3>(fn: (arg1: T1, arg2: T2, arg3: T3, callback: (err: Error | null) => void) => void): (arg1: T1, arg2: T2, arg3: T3) => Promise<void>;
+    export function promisify<T1, T2, T3, T4, TResult>(fn: (arg1: T1, arg2: T2, arg3: T3, arg4: T4, callback: (err: Error | null, result: TResult) => void) => void): (arg1: T1, arg2: T2, arg3: T3, arg4: T4) => Promise<TResult>;
+    export function promisify<T1, T2, T3, T4>(fn: (arg1: T1, arg2: T2, arg3: T3, arg4: T4, callback: (err: Error | null) => void) => void): (arg1: T1, arg2: T2, arg3: T3, arg4: T4) => Promise<void>;
+    export function promisify<T1, T2, T3, T4, T5, TResult>(fn: (arg1: T1, arg2: T2, arg3: T3, arg4: T4, arg5: T5, callback: (err: Error | null, result: TResult) => void) => void): (arg1: T1, arg2: T2, arg3: T3, arg4: T4, arg5: T5) => Promise<TResult>;
+    export function promisify<T1, T2, T3, T4, T5>(fn: (arg1: T1, arg2: T2, arg3: T3, arg4: T4, arg5: T5, callback: (err: Error | null) => void) => void): (arg1: T1, arg2: T2, arg3: T3, arg4: T4, arg5: T5) => Promise<void>;
     export function promisify(fn: Function): Function;
     export namespace promisify {
         const custom: symbol;
diff --git a/types/node/v8/index.d.ts b/types/node/v8/index.d.ts
index 5d672296f2..7ee216c569 100644
--- a/types/node/v8/index.d.ts
+++ b/types/node/v8/index.d.ts
@@ -18,6 +18,7 @@
 //                 Hannes Magnusson <https://github.com/Hannes-Magnusson-CK>
 //                 Alberto Schiabel <https://github.com/jkomyno>
 //                 Huw <https://github.com/hoo29>
+//                 Nicolas Even <https://github.com/n-e>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 // TypeScript Version: 2.1
 
@@ -5532,18 +5533,18 @@ declare module "util" {
     export function callbackify<T1, T2, T3, T4, T5, T6, TResult>(fn: (arg1: T1, arg2: T2, arg3: T3, arg4: T4, arg5: T5, arg6: T6) => Promise<TResult>): (arg1: T1, arg2: T2, arg3: T3, arg4: T4, arg5: T5, arg6: T6, callback: (err: NodeJS.ErrnoException, result: TResult) => void) => void;
 
     export function promisify<TCustom extends Function>(fn: CustomPromisify<TCustom>): TCustom;
-    export function promisify<TResult>(fn: (callback: (err: Error, result: TResult) => void) => void): () => Promise<TResult>;
-    export function promisify(fn: (callback: (err: Error) => void) => void): () => Promise<void>;
-    export function promisify<T1, TResult>(fn: (arg1: T1, callback: (err: Error, result: TResult) => void) => void): (arg1: T1) => Promise<TResult>;
-    export function promisify<T1>(fn: (arg1: T1, callback: (err: Error) => void) => void): (arg1: T1) => Promise<void>;
-    export function promisify<T1, T2, TResult>(fn: (arg1: T1, arg2: T2, callback: (err: Error, result: TResult) => void) => void): (arg1: T1, arg2: T2) => Promise<TResult>;
-    export function promisify<T1, T2>(fn: (arg1: T1, arg2: T2, callback: (err: Error) => void) => void): (arg1: T1, arg2: T2) => Promise<void>;
-    export function promisify<T1, T2, T3, TResult>(fn: (arg1: T1, arg2: T2, arg3: T3, callback: (err: Error, result: TResult) => void) => void): (arg1: T1, arg2: T2, arg3: T3) => Promise<TResult>;
-    export function promisify<T1, T2, T3>(fn: (arg1: T1, arg2: T2, arg3: T3, callback: (err: Error) => void) => void): (arg1: T1, arg2: T2, arg3: T3) => Promise<void>;
-    export function promisify<T1, T2, T3, T4, TResult>(fn: (arg1: T1, arg2: T2, arg3: T3, arg4: T4, callback: (err: Error, result: TResult) => void) => void): (arg1: T1, arg2: T2, arg3: T3, arg4: T4) => Promise<TResult>;
-    export function promisify<T1, T2, T3, T4>(fn: (arg1: T1, arg2: T2, arg3: T3, arg4: T4, callback: (err: Error) => void) => void): (arg1: T1, arg2: T2, arg3: T3, arg4: T4) => Promise<void>;
-    export function promisify<T1, T2, T3, T4, T5, TResult>(fn: (arg1: T1, arg2: T2, arg3: T3, arg4: T4, arg5: T5, callback: (err: Error, result: TResult) => void) => void): (arg1: T1, arg2: T2, arg3: T3, arg4: T4, arg5: T5) => Promise<TResult>;
-    export function promisify<T1, T2, T3, T4, T5>(fn: (arg1: T1, arg2: T2, arg3: T3, arg4: T4, arg5: T5, callback: (err: Error) => void) => void): (arg1: T1, arg2: T2, arg3: T3, arg4: T4, arg5: T5) => Promise<void>;
+    export function promisify<TResult>(fn: (callback: (err: Error | null, result: TResult) => void) => void): () => Promise<TResult>;
+    export function promisify(fn: (callback: (err: Error | null) => void) => void): () => Promise<void>;
+    export function promisify<T1, TResult>(fn: (arg1: T1, callback: (err: Error | null, result: TResult) => void) => void): (arg1: T1) => Promise<TResult>;
+    export function promisify<T1>(fn: (arg1: T1, callback: (err: Error | null) => void) => void): (arg1: T1) => Promise<void>;
+    export function promisify<T1, T2, TResult>(fn: (arg1: T1, arg2: T2, callback: (err: Error | null, result: TResult) => void) => void): (arg1: T1, arg2: T2) => Promise<TResult>;
+    export function promisify<T1, T2>(fn: (arg1: T1, arg2: T2, callback: (err: Error | null) => void) => void): (arg1: T1, arg2: T2) => Promise<void>;
+    export function promisify<T1, T2, T3, TResult>(fn: (arg1: T1, arg2: T2, arg3: T3, callback: (err: Error | null, result: TResult) => void) => void): (arg1: T1, arg2: T2, arg3: T3) => Promise<TResult>;
+    export function promisify<T1, T2, T3>(fn: (arg1: T1, arg2: T2, arg3: T3, callback: (err: Error | null) => void) => void): (arg1: T1, arg2: T2, arg3: T3) => Promise<void>;
+    export function promisify<T1, T2, T3, T4, TResult>(fn: (arg1: T1, arg2: T2, arg3: T3, arg4: T4, callback: (err: Error | null, result: TResult) => void) => void): (arg1: T1, arg2: T2, arg3: T3, arg4: T4) => Promise<TResult>;
+    export function promisify<T1, T2, T3, T4>(fn: (arg1: T1, arg2: T2, arg3: T3, arg4: T4, callback: (err: Error | null) => void) => void): (arg1: T1, arg2: T2, arg3: T3, arg4: T4) => Promise<void>;
+    export function promisify<T1, T2, T3, T4, T5, TResult>(fn: (arg1: T1, arg2: T2, arg3: T3, arg4: T4, arg5: T5, callback: (err: Error | null, result: TResult) => void) => void): (arg1: T1, arg2: T2, arg3: T3, arg4: T4, arg5: T5) => Promise<TResult>;
+    export function promisify<T1, T2, T3, T4, T5>(fn: (arg1: T1, arg2: T2, arg3: T3, arg4: T4, arg5: T5, callback: (err: Error | null) => void) => void): (arg1: T1, arg2: T2, arg3: T3, arg4: T4, arg5: T5) => Promise<void>;
     export function promisify(fn: Function): Function;
     export namespace promisify {
         const custom: symbol;