diff --git a/docs/api-operation.md b/docs/api-operation.md
index a087efa9..f166bdac 100644
--- a/docs/api-operation.md
+++ b/docs/api-operation.md
@@ -170,7 +170,7 @@ const data = await sharp(input).sharpen({ sigma: 2 }).toBuffer();
 const data = await sharp(input)
   .sharpen({
     sigma: 2,
-    m1: 0
+    m1: 0,
     m2: 3,
     x1: 3,
     y2: 15,
diff --git a/lib/operation.js b/lib/operation.js
index 55782c6e..02652426 100644
--- a/lib/operation.js
+++ b/lib/operation.js
@@ -205,7 +205,7 @@ function affine (matrix, options) {
  * const data = await sharp(input)
  *   .sharpen({
  *     sigma: 2,
- *     m1: 0
+ *     m1: 0,
  *     m2: 3,
  *     x1: 3,
  *     y2: 15,