diff --git a/README.md b/README.md
index efa93792..928225de 100644
--- a/README.md
+++ b/README.md
@@ -214,7 +214,7 @@ You can universally customize IPX configuration using `IPX_*` environment variab
 | tint           | [Docs](https://sharp.pixelplumbing.com/api-colour#tint)         | `/tint_1098123/buffalo.png`                          |
 | grayscale      | [Docs](https://sharp.pixelplumbing.com/api-colour#grayscale)    | `/grayscale/buffalo.png`                             |
 | flatten        | [Docs](https://sharp.pixelplumbing.com/api-operation#flatten)   | `/flatten/buffalo.png`                               | Remove alpha channel, if any, and replace with background colour.                                                                                                 |
-| modulate       | [Docs](https://sharp.pixelplumbing.com/api-operation#modulate)  | `/modulate_brightness_saturation_hue/buffalo.png`    | Transforms the image using brightness, saturation and hue rotation.                                                                                               |
+| modulate       | [Docs](https://sharp.pixelplumbing.com/api-operation#modulate)  | `/modulate_{brightness}_{saturation}_{hue}_{lightness}/buffalo.png`    | Transforms the image using brightness, saturation, hue rotation and lightness.                                                                                               |
 | crop           | [Docs](https://sharp.pixelplumbing.com/api-resize#extract)      | `/crop_{left}_{top}_{width}_{height}/buffalo.png`    | Alias for extract. Extract/crop a region of the image.                                                                                                            |
 | animated / a   | -                                                               | `/animated/buffalo.gif` or `/a/buffalo.gif`          | Experimental                                                                                                                                                      |
 
diff --git a/src/handlers/handlers.ts b/src/handlers/handlers.ts
index 0c19dc3c..d50bec1c 100644
--- a/src/handlers/handlers.ts
+++ b/src/handlers/handlers.ts
@@ -240,12 +240,13 @@ export const threshold: Handler = {
 
 // https://sharp.pixelplumbing.com/api-operation#modulate
 export const modulate: Handler = {
-  args: [VArg],
-  apply: (_context, pipe, brightness, saturation, hue) => {
+  args: [VArg, VArg, VArg, VArg],
+  apply: (_context, pipe, brightness, saturation, hue, lightness) => {
     return pipe.modulate({
       brightness,
       saturation,
       hue,
+      lightness,
     });
   },
 };
diff --git a/test/handlers/handlers.test.ts b/test/handlers/handlers.test.ts
index b99b5764..83f5a3d3 100644
--- a/test/handlers/handlers.test.ts
+++ b/test/handlers/handlers.test.ts
@@ -313,12 +313,13 @@ describe("handlers", () => {
       modulate: vi.fn(),
     };
 
-    modulate.apply({} as any, sharpMock as any, 100, 200, 300);
+    modulate.apply({} as any, sharpMock as any, 100, 200, 300, 400);
 
     expect(sharpMock.modulate).toHaveBeenCalledWith({
       brightness: 100,
       saturation: 200,
       hue: 300,
+      lightness: 400,
     });
   });