diff --git a/_config/tests.yml b/_config/tests.yml
new file mode 100644
index 00000000..0851062f
--- /dev/null
+++ b/_config/tests.yml
@@ -0,0 +1,8 @@
+---
+Name: queuedjobstests
+---
+SilverStripe\Core\Injector\Injector:
+  SilverStripe\Dev\State\SapphireTestState:
+    properties:
+      States:
+        queuedjobsstate: '%$Symbiote\QueuedJobs\Dev\State\QueuedJobsTestState'
diff --git a/src/Dev/State/QueuedJobsTestState.php b/src/Dev/State/QueuedJobsTestState.php
new file mode 100644
index 00000000..c4fce406
--- /dev/null
+++ b/src/Dev/State/QueuedJobsTestState.php
@@ -0,0 +1,37 @@
+<?php
+
+namespace Symbiote\QueuedJobs\Dev\State;
+
+use SilverStripe\Core\Config\Config;
+use SilverStripe\Dev\SapphireTest;
+use SilverStripe\Dev\State\TestState;
+use Symbiote\QueuedJobs\Services\QueuedJobService;
+
+class QueuedJobsTestState implements TestState
+{
+    /**
+     * Never run the shutdown handler during unit tests
+     *
+     * @param SapphireTest $test
+     */
+    public function setUp(SapphireTest $test)
+    {
+
+        Config::modify()->set(QueuedJobService::class, 'use_shutdown_function', false);
+    }
+
+    public function tearDown(SapphireTest $test)
+    {
+        // noop
+    }
+
+    public function setUpOnce($class)
+    {
+        // noop
+    }
+
+    public function tearDownOnce($class)
+    {
+        // noop
+    }
+}
diff --git a/src/QJUtils.php b/src/QJUtils.php
index 7c41ec4b..61ecec59 100644
--- a/src/QJUtils.php
+++ b/src/QJUtils.php
@@ -91,7 +91,7 @@ protected function recursiveQuote($val)
      */
     public function ajaxResponse($message, $status)
     {
-        return Convert::raw2json(array(
+        return json_encode(array(
             'message' => $message,
             'status' => $status,
         ));
diff --git a/src/Services/QueuedJobService.php b/src/Services/QueuedJobService.php
index 23a02a04..4fa7e9ec 100644
--- a/src/Services/QueuedJobService.php
+++ b/src/Services/QueuedJobService.php
@@ -266,14 +266,8 @@ protected function copyDescriptorToJob($jobDescriptor, $job)
         $messages = @unserialize($jobDescriptor->SavedJobMessages);
 
         if (!$jobData) {
-            // SS's convert:: function doesn't do this detection for us!!
-            if (function_exists('json_decode')) {
-                $jobData = json_decode($jobDescriptor->SavedJobData);
-                $messages = json_decode($jobDescriptor->SavedJobMessages);
-            } else {
-                $jobData = Convert::json2obj($jobDescriptor->SavedJobData);
-                $messages = Convert::json2obj($jobDescriptor->SavedJobMessages);
-            }
+            $jobData = json_decode($jobDescriptor->SavedJobData);
+            $messages = json_decode($jobDescriptor->SavedJobMessages);
         }
 
         $job->setJobData(