diff --git a/docs/api-operation.md b/docs/api-operation.md
index 576b7ff9..5c3e6be9 100644
--- a/docs/api-operation.md
+++ b/docs/api-operation.md
@@ -329,10 +329,10 @@ Apply the linear formula a \* input + b to the image (levels adjustment)
 
 **Parameters**
 
--   `a` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)?** multiplier (optional, default `1.0`)
--   `b` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)?** offset (optional, default `0.0`)
+-   `a` **[Number](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number)** multiplier (optional, default `1.0`)
+-   `b` **[Number](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number)** offset (optional, default `0.0`)
 
 
--   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters
+-   Throws **[Error](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters
 
 Returns **Sharp** 
diff --git a/docs/changelog.md b/docs/changelog.md
index 5d719c63..927d04a5 100644
--- a/docs/changelog.md
+++ b/docs/changelog.md
@@ -4,6 +4,12 @@
 
 Requires libvips v8.6.1.
 
+#### v0.19.1 - TBD
+
+* Expose libvips' linear transform feature.
+  [#1024](https://github.com/lovell/sharp/pull/1024)
+  [@3epnm](https://github.com/3epnm)
+
 #### v0.19.0 - 11<sup>th</sup> January 2018
 
 * Expose offset coordinates of strategy-based crop.
diff --git a/docs/index.md b/docs/index.md
index c72d4abb..dcaf8fd1 100644
--- a/docs/index.md
+++ b/docs/index.md
@@ -105,6 +105,8 @@ the help and code contributions of the following people:
 * [Matthew McEachen](https://github.com/mceachen)
 * [Jarda Kotěšovec](https://github.com/jardakotesovec)
 * [Kenric D'Souza](https://github.com/AzureByte)
+* [Oleh Aleinyk](https://github.com/oaleynik)
+* [Marcel Bretschneider](https://github.com/3epnm)
 
 Thank you!
 
diff --git a/package.json b/package.json
index e37e3f69..38799ea3 100644
--- a/package.json
+++ b/package.json
@@ -43,7 +43,8 @@
     "Matthew McEachen <matthew+github@mceachen.org>",
     "Jarda Kotěšovec <jarda.kotesovec@gmail.com>",
     "Kenric D'Souza <kenric.dsouza@gmail.com>",
-    "Oleh Aleinyk <oleg.aleynik@gmail.com>"
+    "Oleh Aleinyk <oleg.aleynik@gmail.com>",
+    "Marcel Bretschneider <marcel.bretschneider@gmail.com>"
   ],
   "scripts": {
     "clean": "rm -rf node_modules/ build/ vendor/ coverage/ test/fixtures/output.*",
@@ -74,12 +75,12 @@
     "vips"
   ],
   "dependencies": {
-    "color": "^2.0.1",
+    "color": "^3.0.0",
     "detect-libc": "^1.0.3",
     "nan": "^2.8.0",
-    "semver": "^5.4.1",
+    "semver": "^5.5.0",
     "simple-get": "^2.7.0",
-    "tar": "^4.2.0",
+    "tar": "^4.3.2",
     "tunnel-agent": "^0.6.0"
   },
   "devDependencies": {
@@ -88,7 +89,7 @@
     "documentation": "^5.3.5",
     "exif-reader": "^1.0.2",
     "icc": "^1.0.0",
-    "mocha": "^4.1.0",
+    "mocha": "^5.0.0",
     "nyc": "^11.4.1",
     "rimraf": "^2.6.2",
     "semistandard": "^12.0.0",