diff --git a/docs/api-operation.md b/docs/api-operation.md
index d1c9dd04..86b76528 100644
--- a/docs/api-operation.md
+++ b/docs/api-operation.md
@@ -24,7 +24,10 @@
 Rotate the output image by either an explicit angle
 or auto-orient based on the EXIF `Orientation` tag.
 
-Use this method without angle to determine the angle from EXIF data.
+If an angle is provided, it is converted to a valid 90/180/270deg rotation.
+For example, `-450` will produce a 270deg rotation.
+
+If no angle is provided, it is determined from the EXIF data.
 Mirroring is supported and may infer the use of a flip operation.
 
 The use of `rotate` implies the removal of the EXIF `Orientation` tag, if any.
@@ -34,7 +37,7 @@ for example `rotate(x).extract(y)` will produce a different result to `extract(y
 
 **Parameters**
 
--   `angle` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** 0, 90, 180 or 270. (optional, default `auto`)
+-   `angle` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** angle of rotation, must be a multiple of 90. (optional, default `auto`)
 
 **Examples**
 
diff --git a/docs/changelog.md b/docs/changelog.md
index 12ed2d64..ccc6e34a 100644
--- a/docs/changelog.md
+++ b/docs/changelog.md
@@ -49,6 +49,14 @@ Requires libvips v8.5.5.
   [#783](https://github.com/lovell/sharp/pull/783)
   [@YvesBos](https://github.com/YvesBos)
 
+* Add support for rotation using any multiple of +/-90 degrees.
+  [#791](https://github.com/lovell/sharp/pull/791)
+  [@ncoden](https://github.com/ncoden)
+
+* Add "jpg" alias to toFormat as shortened form of "jpeg".
+  [#814](https://github.com/lovell/sharp/pull/814)
+  [@jingsam](https://github.com/jingsam)
+
 ### v0.17 - "*quill*"
 
 Requires libvips v8.4.2.
diff --git a/lib/operation.js b/lib/operation.js
index c0b19539..692b68eb 100644
--- a/lib/operation.js
+++ b/lib/operation.js
@@ -9,7 +9,7 @@ const is = require('./is');
  * If an angle is provided, it is converted to a valid 90/180/270deg rotation.
  * For example, `-450` will produce a 270deg rotation.
  *
- * If no angle is provided, it is determined the from EXIF data.
+ * If no angle is provided, it is determined from the EXIF data.
  * Mirroring is supported and may infer the use of a flip operation.
  *
  * The use of `rotate` implies the removal of the EXIF `Orientation` tag, if any.
diff --git a/package.json b/package.json
index a984a89e..ceafeb65 100644
--- a/package.json
+++ b/package.json
@@ -75,14 +75,14 @@
     "tar": "^3.1.3"
   },
   "devDependencies": {
-    "async": "^2.4.0",
-    "cc": "^1.0.0",
+    "async": "^2.4.1",
+    "cc": "^1.0.1",
     "documentation": "^4.0.0-rc.1",
     "exif-reader": "^1.0.2",
     "icc": "^1.0.0",
     "mocha": "^3.4.1",
     "nyc": "^10.3.2",
-    "rimraf": "^2.5.4",
+    "rimraf": "^2.6.1",
     "semistandard": "^11.0.0",
     "unzip": "^0.1.11"
   },