diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0b47f03b..9fc06c6d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Changelog
 
+## 0.7.3 - 2016-02-22
+ * If a response doesn't have a 'ResponseMessages' Property (such as `GetUserAvailabilityResponseType`), then don't drill
+ down response levels and instead simply return the response
+
 ## 0.7.2 - 2016-01-26
  * Added `ContactsAPI` for simple usage
  * Added examples for the ContactsAPI
diff --git a/src/API/ExchangeWebServices.php b/src/API/ExchangeWebServices.php
index 5617c9d9..93a41714 100644
--- a/src/API/ExchangeWebServices.php
+++ b/src/API/ExchangeWebServices.php
@@ -333,6 +333,10 @@ protected function processResponse($response)
             return $response;
         }
 
+        if (!$response->exists('responseMessages')) {
+            return $response;
+        }
+
         $response = $response->getResponseMessages();
         $response = $this->drillDownResponseLevels($response);