diff --git a/lib/index.d.ts b/lib/index.d.ts
index a4c54d64..a6daf1f2 100644
--- a/lib/index.d.ts
+++ b/lib/index.d.ts
@@ -640,7 +640,7 @@ declare namespace sharp {
          * @param withMetadata
          * @throws {Error} Invalid parameters.
          */
-        withMetadata(withMetadata?: WriteableMetadata): Sharp;
+        withMetadata(withMetadata?: boolean | WriteableMetadata): Sharp;
 
         /**
          * Use these JPEG options for output image.
@@ -1275,10 +1275,10 @@ declare namespace sharp {
     }
 
     interface NormaliseOptions {
-      /** Percentile below which luminance values will be underexposed. */
-      lower?: number | undefined;
-      /** Percentile above which luminance values will be overexposed. */
-      upper?: number | undefined;
+        /** Percentile below which luminance values will be underexposed. */
+        lower?: number | undefined;
+        /** Percentile above which luminance values will be overexposed. */
+        upper?: number | undefined;
     }
 
     interface ResizeOptions {
diff --git a/test/types/sharp.test-d.ts b/test/types/sharp.test-d.ts
index 2500b919..38f34171 100644
--- a/test/types/sharp.test-d.ts
+++ b/test/types/sharp.test-d.ts
@@ -659,3 +659,6 @@ sharp('input.tiff').webp({ preset: 'drawing' }).toFile('out.webp');
 sharp('input.tiff').webp({ preset: 'text' }).toFile('out.webp');
 sharp('input.tiff').webp({ preset: 'default' }).toFile('out.webp');
 
+// Allow a boolean or an object for metadata options.
+// https://github.com/lovell/sharp/issues/3822
+sharp(input).withMetadata().withMetadata({}).withMetadata(false);