diff --git a/github-electron/github-electron-main-tests.ts b/github-electron/github-electron-main-tests.ts
index a1b952889..df20d5a54 100644
--- a/github-electron/github-electron-main-tests.ts
+++ b/github-electron/github-electron-main-tests.ts
@@ -10,6 +10,7 @@ import {
 	Menu,
 	MenuItem,
 	powerMonitor,
+	powerSaveBlocker,
 	protocol,
 	Tray,
 	clipboard,
@@ -489,6 +490,14 @@ app.on('ready', () => {
 	});
 });
 
+// power-save-blocker
+// https://github.com/atom/electron/blob/master/docs/api/power-save-blocker.md
+
+var id = powerSaveBlocker.start('prevent-display-sleep');
+console.log(powerSaveBlocker.isStarted(id));
+
+powerSaveBlocker.stop(id);
+
 // protocol
 // https://github.com/atom/electron/blob/master/docs/api/protocol.md
 
diff --git a/github-electron/github-electron.power-save-blocker.d.ts b/github-electron/github-electron.power-save-blocker.d.ts
index 5ecc2ad3c..31135e438 100644
--- a/github-electron/github-electron.power-save-blocker.d.ts
+++ b/github-electron/github-electron.power-save-blocker.d.ts
@@ -4,10 +4,26 @@
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 
 declare namespace Electron {
-
+	/**
+	 * The powerSaveBlocker module is used to block the system from entering
+	 * low-power (sleep) mode and thus allowing the app to keep the system and screen active.
+	 */
 	interface PowerSaveBlocker {
-		start(type: string): number;
+		/**
+		 * Starts preventing the system from entering lower-power mode.
+		 * @returns an integer identifying the power save blocker.
+		 * Note: prevent-display-sleep has higher has precedence over prevent-app-suspension.
+		 */
+		start(type: 'prevent-app-suspension' | 'prevent-display-sleep'): number;
+		/**
+		 * @param id The power save blocker id returned by powerSaveBlocker.start.
+		 * Stops the specified power save blocker.
+		 */
 		stop(id: number): void;
+		/**
+		 * @param id The power save blocker id returned by powerSaveBlocker.start.
+		 * @returns a boolean whether the corresponding powerSaveBlocker has started.
+		 */
 		isStarted(id: number): boolean;
 	}
 }