diff --git a/CHANGES.md b/CHANGES.md
index 8e23b559f5b2..3cc67a3a3c3d 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -20,6 +20,7 @@ Change Log
 * Fixed a bug that caused all models to use the same highlight color. [#4798] (https://github.com/AnalyticalGraphicsInc/cesium/pull/4798)
 * Fixed KML for when color is an empty string [#4826](https://github.com/AnalyticalGraphicsInc/cesium/pull/4826)
 * Added support for WMS version 1.3 by using CRS vice SRS query string parameter to request projection. SRS is still used for older versions.
+* The attribute `perInstanceAttribute` of `DebugAppearance` has been made optional and defaults to `false`.
 
 ### 1.29 - 2017-01-02
 * Improved 3D Models
diff --git a/Source/Scene/DebugAppearance.js b/Source/Scene/DebugAppearance.js
index 9e4137483a7b..288fa7ca075f 100644
--- a/Source/Scene/DebugAppearance.js
+++ b/Source/Scene/DebugAppearance.js
@@ -26,7 +26,7 @@ define([
      *
      * @param {Object} options Object with the following properties:
      * @param {String} options.attributeName The name of the attribute to visualize.
-     * @param {Boolean} options.perInstanceAttribute Boolean that determines whether this attribute is a per-instance geometry attribute.
+     * @param {Boolean} [options.perInstanceAttribute=false] Boolean that determines whether this attribute is a per-instance geometry attribute.
      * @param {String} [options.glslDatatype='vec3'] The GLSL datatype of the attribute.  Supported datatypes are <code>float</code>, <code>vec2</code>, <code>vec3</code>, and <code>vec4</code>.
      * @param {String} [options.vertexShaderSource] Optional GLSL vertex shader source to override the default vertex shader.
      * @param {String} [options.fragmentShaderSource] Optional GLSL fragment shader source to override the default fragment shader.
@@ -51,10 +51,11 @@ define([
         if (!defined(attributeName)) {
             throw new DeveloperError('options.attributeName is required.');
         }
+        //>>includeEnd('debug');
+
         if (!defined(perInstanceAttribute)) {
-            throw new DeveloperError('options.perInstanceAttribute is required.');
+            perInstanceAttribute = false;
         }
-        //>>includeEnd('debug');
 
         var glslDatatype = defaultValue(options.glslDatatype, 'vec3');
         var varyingName = 'v_' + attributeName;