diff --git a/src/body/Body.js b/src/body/Body.js
index f2e378d..2190968 100644
--- a/src/body/Body.js
+++ b/src/body/Body.js
@@ -673,6 +673,7 @@ var Axes = require('../geometry/Axes');
      * @property type
      * @type string
      * @default "body"
+     * @readOnly
      */
 
     /**
diff --git a/src/body/Composite.js b/src/body/Composite.js
index af5ef4c..397327b 100644
--- a/src/body/Composite.js
+++ b/src/body/Composite.js
@@ -596,6 +596,7 @@ var Body = require('./Body');
      * @property type
      * @type string
      * @default "composite"
+     * @readOnly
      */
 
     /**
diff --git a/src/constraint/Constraint.js b/src/constraint/Constraint.js
index 1ec35f1..7795ea3 100644
--- a/src/constraint/Constraint.js
+++ b/src/constraint/Constraint.js
@@ -297,6 +297,7 @@ var Common = require('../core/Common');
      * @property type
      * @type string
      * @default "constraint"
+     * @readOnly
      */
 
     /**
diff --git a/src/constraint/MouseConstraint.js b/src/constraint/MouseConstraint.js
index 31e3f32..689784b 100644
--- a/src/constraint/MouseConstraint.js
+++ b/src/constraint/MouseConstraint.js
@@ -220,6 +220,7 @@ var Bounds = require('../geometry/Bounds');
      * @property type
      * @type string
      * @default "constraint"
+     * @readOnly
      */
 
     /**