diff --git a/types/expo/expo-tests.tsx b/types/expo/expo-tests.tsx
index 564611bb60..f5aade3766 100644
--- a/types/expo/expo-tests.tsx
+++ b/types/expo/expo-tests.tsx
@@ -267,8 +267,8 @@ const barcodeReadCallback = () => {};
 );
 
 async () => {
-    await Brightness.setBrightnessAsync(.6);
-    await Brightness.setSystemBrightnessAsync(.7);
+    await Brightness.setBrightnessAsync(0.65);
+    await Brightness.setSystemBrightnessAsync(0.75);
     const br1 = await Brightness.getBrightnessAsync();
     const br2 = await Brightness.getSystemBrightnessAsync();
 };
diff --git a/types/expo/index.d.ts b/types/expo/index.d.ts
index 641c3f1ded..1c3e528b0a 100644
--- a/types/expo/index.d.ts
+++ b/types/expo/index.d.ts
@@ -732,13 +732,32 @@ export class BlurView extends Component<BlurViewProps> { }
 // #endregion
 
 /**
- * Brightness
+ * An API to get and set screen brightness.
  */
 export namespace Brightness {
-    function setBrightnessAsync(brightnessValue: FloatFromZeroToOne): Promise<void>;
-    function getBrightnessAsync(): Promise<FloatFromZeroToOne>;
-    function getSystemBrightnessAsync(): Promise<FloatFromZeroToOne>;
-    function setSystemBrightnessAsync(brightnessValue: FloatFromZeroToOne): Promise<void>;
+    /** Sets screen brightness. */
+    function setBrightnessAsync(
+        /** A number between `0` and `1`, representing the desired screen brightness. */
+        brightnessValue: number
+    ): Promise<void>;
+
+    /**
+     * Gets screen brightness.
+     * @returns A Promise that is resolved with a number between `0` and `1`, representing the current screen brightness.
+     */
+    function getBrightnessAsync(): Promise<number>;
+
+    /**
+     * Gets global system screen brightness.
+     * @returns A Promise that is resolved with a number between `0` and `1`, representing the current system screen brightness.
+     */
+    function getSystemBrightnessAsync(): Promise<number>;
+
+    /** Sets global system screen brightness, requires `WRITE_SETTINGS` permissions on Android. */
+    function setSystemBrightnessAsync(
+        /** A number between `0` and `1`, representing the desired screen brightness. */
+        brightnessValue: number
+    ): Promise<void>;
 }
 
 // #region Camera