diff --git a/lib/Group.js b/lib/Group.js
index 918a43d..56c326b 100644
--- a/lib/Group.js
+++ b/lib/Group.js
@@ -16,7 +16,7 @@ class Group {
    * @param {string} id Id
    */
   constructor(id, device) {
-    this.properties = DEFAULT_PROPERTIES;
+    this.properties = Object.assign({}, DEFAULT_PROPERTIES);
     this.id         = _.isEmpty(id) ? DEFAULT_PROPERTIES.id : id;
   }
 
diff --git a/lib/Message.js b/lib/Message.js
index 4e2554b..9723b82 100644
--- a/lib/Message.js
+++ b/lib/Message.js
@@ -25,7 +25,7 @@ class Message {
    * @param {object} options Options
    */
   constructor(options) {
-    this.properties = DEFAULT_PROPERTIES;
+    this.properties = Object.assign({}, DEFAULT_PROPERTIES);
 
     for (let i in options) {
       this[i] = options[i];
diff --git a/lib/Receipt.js b/lib/Receipt.js
index 9e07fc5..fb0f880 100644
--- a/lib/Receipt.js
+++ b/lib/Receipt.js
@@ -25,7 +25,7 @@ class Receipt {
    * @param {object} results Results
    */
   constructor(id, results) {
-    this.properties    = DEFAULT_PROPERTIES;
+    this.properties    = Object.assign({}, DEFAULT_PROPERTIES);
     this.properties.id = id;
 
     for (let i in results) {
diff --git a/lib/User.js b/lib/User.js
index af72b56..97be7bd 100644
--- a/lib/User.js
+++ b/lib/User.js
@@ -18,7 +18,7 @@ class User {
    * @param {string} device Device name
    */
   constructor(id, device) {
-    this.properties = DEFAULT_PROPERTIES;
+    this.properties = Object.assign({}, DEFAULT_PROPERTIES);
     this.id         = _.isEmpty(id) ? DEFAULT_PROPERTIES.id : id;
     this.device     = _.isEmpty(device) ? DEFAULT_PROPERTIES.device : device;
   }
diff --git a/package.json b/package.json
index bcc1423..ebf29c1 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "chump",
-  "version": "1.0.3",
+  "version": "1.0.4",
   "description": "Pushover.net client for Node.js",
   "keywords": [
     "pushover",
@@ -34,4 +34,4 @@
     "sinon":            "1.17.0",
     "mockery":          "1.4.0"
   }
-}
\ No newline at end of file
+}