diff --git a/src/extract/canvas/CanvasExtract.js b/src/extract/canvas/CanvasExtract.js
index 5809774..b82832d 100644
--- a/src/extract/canvas/CanvasExtract.js
+++ b/src/extract/canvas/CanvasExtract.js
@@ -16,6 +16,13 @@
     constructor(renderer)
     {
         this.renderer = renderer;
+        /**
+         * Collection of methods for extracting data (image, pixels, etc.) from a display object or render texture
+         *
+         * @member {PIXI.CanvasExtract} extract
+         * @memberof PIXI.CanvasRenderer#
+         * @see PIXI.CanvasExtract
+         */
         renderer.extract = this;
     }
 

diff --git a/src/extract/canvas/CanvasExtract.js b/src/extract/canvas/CanvasExtract.js
index 5809774..b82832d 100644
--- a/src/extract/canvas/CanvasExtract.js
+++ b/src/extract/canvas/CanvasExtract.js
@@ -16,6 +16,13 @@
     constructor(renderer)
     {
         this.renderer = renderer;
+        /**
+         * Collection of methods for extracting data (image, pixels, etc.) from a display object or render texture
+         *
+         * @member {PIXI.CanvasExtract} extract
+         * @memberof PIXI.CanvasRenderer#
+         * @see PIXI.CanvasExtract
+         */
         renderer.extract = this;
     }
 
diff --git a/src/extract/webgl/WebGLExtract.js b/src/extract/webgl/WebGLExtract.js
index 523e7fc..fd3a61e 100644
--- a/src/extract/webgl/WebGLExtract.js
+++ b/src/extract/webgl/WebGLExtract.js
@@ -17,6 +17,13 @@
     constructor(renderer)
     {
         this.renderer = renderer;
+        /**
+         * Collection of methods for extracting data (image, pixels, etc.) from a display object or render texture
+         *
+         * @member {PIXI.WebGLExtract} extract
+         * @memberof PIXI.WebGLRenderer#
+         * @see PIXI.WebGLExtract
+         */
         renderer.extract = this;
     }