diff --git a/docs/api-operation.md b/docs/api-operation.md
index a158c457..ced28660 100644
--- a/docs/api-operation.md
+++ b/docs/api-operation.md
@@ -145,7 +145,7 @@ See [libvips sharpen][8] operation.
 
 ### Parameters
 
-*   `options` **[Object][2]?** if present, is an Object with optional attributes.
+*   `options` **([Object][2] | [number][1])?** if present, is an Object with attributes or (deprecated) a number for `options.sigma`.
 
     *   `options.sigma` **[number][1]?** the sigma of the Gaussian mask, where `sigma = 1 + radius / 2`.
     *   `options.m1` **[number][1]** the level of sharpening to apply to "flat" areas. (optional, default `1.0`)
@@ -153,6 +153,8 @@ See [libvips sharpen][8] operation.
     *   `options.x1` **[number][1]** threshold between "flat" and "jagged" (optional, default `2.0`)
     *   `options.y2` **[number][1]** maximum amount of brightening. (optional, default `10.0`)
     *   `options.y3` **[number][1]** maximum amount of darkening. (optional, default `20.0`)
+*   `flat` **[number][1]?** (deprecated) see `options.m1`.
+*   `jagged` **[number][1]?** (deprecated) see `options.m2`.
 
 ### Examples
 
diff --git a/lib/operation.js b/lib/operation.js
index 4294c6c1..f3094b39 100644
--- a/lib/operation.js
+++ b/lib/operation.js
@@ -213,17 +213,19 @@ function affine (matrix, options) {
  *   })
  *   .toBuffer();
  *
- * @param {Object} [options] - if present, is an Object with optional attributes.
+ * @param {Object|number} [options] - if present, is an Object with attributes or (deprecated) a number for `options.sigma`.
  * @param {number} [options.sigma] - the sigma of the Gaussian mask, where `sigma = 1 + radius / 2`.
  * @param {number} [options.m1=1.0] - the level of sharpening to apply to "flat" areas.
  * @param {number} [options.m2=2.0] - the level of sharpening to apply to "jagged" areas.
  * @param {number} [options.x1=2.0] - threshold between "flat" and "jagged"
  * @param {number} [options.y2=10.0] - maximum amount of brightening.
  * @param {number} [options.y3=20.0] - maximum amount of darkening.
+ * @param {number} [flat] - (deprecated) see `options.m1`.
+ * @param {number} [jagged] - (deprecated) see `options.m2`.
  * @returns {Sharp}
  * @throws {Error} Invalid parameters
  */
-function sharpen (options) {
+function sharpen (options, flat, jagged) {
   if (!is.defined(options)) {
     // No arguments: default to mild sharpen
     this.options.sharpenSigma = -1;
@@ -234,19 +236,19 @@ function sharpen (options) {
     // Deprecated numeric argument: specific sigma
     this.options.sharpenSigma = options;
     // Deprecated control over flat areas
-    if (is.defined(arguments[1])) {
-      if (is.number(arguments[1]) && is.inRange(arguments[1], 0, 10000)) {
-        this.options.sharpenM1 = arguments[1];
+    if (is.defined(flat)) {
+      if (is.number(flat) && is.inRange(flat, 0, 10000)) {
+        this.options.sharpenM1 = flat;
       } else {
-        throw is.invalidParameterError('flat', 'number between 0 and 10000', arguments[1]);
+        throw is.invalidParameterError('flat', 'number between 0 and 10000', flat);
       }
     }
     // Deprecated control over jagged areas
-    if (is.defined(arguments[2])) {
-      if (is.number(arguments[2]) && is.inRange(arguments[2], 0, 10000)) {
-        this.options.sharpenM2 = arguments[2];
+    if (is.defined(jagged)) {
+      if (is.number(jagged) && is.inRange(jagged, 0, 10000)) {
+        this.options.sharpenM2 = jagged;
       } else {
-        throw is.invalidParameterError('jagged', 'number between 0 and 10000', arguments[2]);
+        throw is.invalidParameterError('jagged', 'number between 0 and 10000', jagged);
       }
     }
   } else if (is.plainObject(options)) {