diff --git a/lib/node.js b/lib/node.js
index f35bed73cb5..23a26714b6a 100644
--- a/lib/node.js
+++ b/lib/node.js
@@ -471,7 +471,21 @@ declare module "url" {
 }
 
 declare module "util" {
-  // TODO
+  declare function debuglog(section: string): (data: any, ...args: any) => void;
+  declare function format(format: string, ...placeholders: any): string;
+  declare function log(string: string): void;
+  declare function inspect(object: any, options?: {
+    showHidden?: boolean;
+    depth?: ?number;
+    colors?: boolean;
+    customInspect?: boolean;
+  }): string;
+  declare function isArray(object: any): boolean;
+  declare function isRegExp(object: any): boolean;
+  declare function isDate(object: any): boolean;
+  declare function isError(object: any): boolean;
+  declare function inherits(constructor: Function, superConstructor: Function): void;
+  declare function deprecate(f: Function, string: string): Function;
 }
 
 declare module "vm" {