diff --git a/README.md b/README.md
index 67ab59f..46d295e 100644
--- a/README.md
+++ b/README.md
@@ -122,7 +122,7 @@ is the first step.
 ```php
 class SurveyForm extends MultiForm {
 
-    public static $start_step = 'SurveyFormPersonalDetailsStep';
+    private static $start_step = 'SurveyFormPersonalDetailsStep';
 
 }
 ```
@@ -141,7 +141,7 @@ the `$start_step` variable *SurveyForm*, but we call it `$next_steps`.
 ```php
 class SurveyFormPersonalDetailsStep extends MultiFormStep {
 
-    public static $next_steps = 'SurveyFormOrganisationDetailsStep';
+    private static $next_steps = 'SurveyFormOrganisationDetailsStep';
 
     public function getFields() {
         return new FieldList(
@@ -167,7 +167,7 @@ SurveyFormOrganisationDetailsStep, then we can do something like this:
 ```php
 class SurveyFormOrganisationDetailsStep extends MultiFormStep {
 
-    public static $is_final_step = true;
+    private static $is_final_step = true;
 
 }
 ```
@@ -334,7 +334,7 @@ Here is an example of how to populate the email address from step 1 in step2 :
 ```php
 class Step1 extends MultiFormStep
 {
-    public static $next_steps = 'Step2';
+    private static $next_steps = 'Step2';
 
     public function getFields() {
         return new FieldList(
@@ -345,7 +345,7 @@ class Step1 extends MultiFormStep
 
 class Step2 extends MultiFormStep
 {
-    public static $next_steps = 'Step3';
+    private static $next_steps = 'Step3';
 
     public function getFields() {
         $fields = new FieldList(
@@ -378,7 +378,7 @@ Here is an example of what we could do here:
 ```php 
 class SurveyForm extends MultiForm {
  
-   public static $start_step = 'SurveyFormPersonalDetailsStep';
+   private static $start_step = 'SurveyFormPersonalDetailsStep';
  
    public function finish($data, $form) {
       parent::finish($data, $form);
@@ -557,7 +557,7 @@ For example:
 ```php
 class SurveyForm extends MultiForm {
 
-   public static $start_step = 'SurveyFormPersonalDetailsStep';
+   private static $start_step = 'SurveyFormPersonalDetailsStep';
 
    public function finish($data, $form) {
       parent::finish($data, $form);
diff --git a/src/Models/MultiForm.php b/src/Models/MultiForm.php
index 7a7f44b..2d9a81c 100644
--- a/src/Models/MultiForm.php
+++ b/src/Models/MultiForm.php
@@ -53,7 +53,7 @@ abstract class MultiForm extends Form
      *
      * @var string Classname of a {@link MultiFormStep} subclass
      */
-    public static $start_step;
+    private static $start_step;
 
     /**
      * Set the casting for these fields.
@@ -78,7 +78,7 @@ abstract class MultiForm extends Form
      *
      * @var array
      */
-    public static $ignored_fields = [
+    private static $ignored_fields = [
         'url',
         'executeForm',
         'SecurityID'
@@ -94,7 +94,7 @@ abstract class MultiForm extends Form
      *
      * @var array
      */
-    public static $actions_exempt_from_validation = [
+    private static $actions_exempt_from_validation = [
         'action_prev'
     ];
 
@@ -146,7 +146,7 @@ abstract class MultiForm extends Form
         $validator = null;
         $applyValidation = true;
 
-        $actionNames = static::$actions_exempt_from_validation;
+        $actionNames = $this->config()->get('actions_exempt_from_validation');
 
         if ($actionNames) {
             foreach ($actionNames as $exemptAction) {
@@ -181,7 +181,7 @@ abstract class MultiForm extends Form
         // Disable security token - we tie a form to a session ID instead
         $this->disableSecurityToken();
 
-        self::$ignored_fields[] = $getVar;
+        $this->config()->merge('ignored_fields', $getVar);
     }
 
     /**
@@ -216,7 +216,7 @@ abstract class MultiForm extends Form
      */
     public function getCurrentStep()
     {
-        $startStepClass = static::$start_step;
+        $startStepClass = $this->config()->get('start_step');
 
         // Check if there was a start step defined on the subclass of MultiForm
         if (!isset($startStepClass)) {
@@ -584,7 +584,7 @@ abstract class MultiForm extends Form
         $currentStep = $this->getCurrentStep();
         if (is_array($data)) {
             foreach ($data as $field => $value) {
-                if (in_array($field, static::$ignored_fields)) {
+                if (in_array($field, $this->config()->get('ignored_fields'))) {
                     unset($data[$field]);
                 }
             }
@@ -647,7 +647,7 @@ abstract class MultiForm extends Form
     {
         $stepsFound = ArrayList::create();
 
-        $firstStep = DataObject::get_one(static::$start_step, "\"SessionID\" = {$this->session->ID}");
+        $firstStep = DataObject::get_one($this->config()->get('start_step'), "\"SessionID\" = {$this->session->ID}");
         $firstStep->LinkingMode = ($firstStep->ID == $this->getCurrentStep()->ID) ? 'current' : 'link';
         $firstStep->setForm($this);
         $stepsFound->push($firstStep);
diff --git a/src/Models/MultiFormStep.php b/src/Models/MultiFormStep.php
index ac52501..5962e20 100644
--- a/src/Models/MultiFormStep.php
+++ b/src/Models/MultiFormStep.php
@@ -40,7 +40,7 @@ class MultiFormStep extends DataObject
      *
      * @var array|string
      */
-    public static $next_steps;
+    private static $next_steps;
 
     /**
      * Each {@link MultiForm} subclass needs at least
@@ -50,7 +50,7 @@ class MultiFormStep extends DataObject
      *
      * @var boolean
      */
-    public static $is_final_step = false;
+    private static $is_final_step = false;
 
     /**
      * This variable determines whether a user can use
@@ -243,7 +243,7 @@ class MultiFormStep extends DataObject
      */
     public function getNextStep()
     {
-        $nextSteps = static::$next_steps;
+        $nextSteps = $this->config()->get('next_steps');
 
         // Check if next_steps have been implemented properly if not the final step
         if (!$this->isFinalStep()) {
@@ -277,7 +277,7 @@ class MultiFormStep extends DataObject
     public function getNextStepFromDatabase()
     {
         if ($this->SessionID && is_numeric($this->SessionID)) {
-            $nextSteps = static::$next_steps;
+            $nextSteps = $this->config()->get('next_steps');
 
             if (is_string($nextSteps)) {
                 return DataObject::get_one($nextSteps, "\"SessionID\" = {$this->SessionID}");
@@ -296,7 +296,7 @@ class MultiFormStep extends DataObject
      */
     public function getNextSteps()
     {
-        return static::$next_steps;
+        return $this->config()->get('next_steps');
     }
 
     /**
@@ -394,7 +394,7 @@ class MultiFormStep extends DataObject
      */
     public function canGoBack()
     {
-        return static::$can_go_back;
+        return $this->config()->get('can_go_back');
     }
 
     /**
@@ -405,7 +405,7 @@ class MultiFormStep extends DataObject
      */
     public function isFinalStep()
     {
-        return static::$is_final_step;
+        return $this->config()->get('is_final_step');
     }
 
     /**
diff --git a/src/tasks/MultiFormPurgeTask.php b/src/tasks/MultiFormPurgeTask.php
index cdcb49a..2765a05 100644
--- a/src/tasks/MultiFormPurgeTask.php
+++ b/src/tasks/MultiFormPurgeTask.php
@@ -27,7 +27,7 @@ class MultiFormPurgeTask extends BuildTask
      *
      * @var int
      */
-    public static $session_expiry_days = 7;
+    private static $session_expiry_days = 7;
 
     /**
      * Run this cron task.
@@ -46,7 +46,7 @@ class MultiFormPurgeTask extends BuildTask
                 $delCount++;
             }
         }
-        echo $delCount . ' session records deleted that were older than ' . self::$session_expiry_days . ' days.';
+        echo $delCount . ' session records deleted that were older than ' . $this->config()->get('session_expiry_days') . ' days.';
     }
 
     /**
@@ -59,7 +59,7 @@ class MultiFormPurgeTask extends BuildTask
     {
         return DataObject::get(
             MultiFormSession::class,
-            "DATEDIFF(NOW(), \"MultiFormSession\".\"Created\") > " . self::$session_expiry_days
+            "DATEDIFF(NOW(), \"MultiFormSession\".\"Created\") > " . $this->config()->get('session_expiry_days')
         );
     }
 }
diff --git a/tests/MultiFormObjectDecoratorTest.php b/tests/MultiFormObjectDecoratorTest.php
index f0da517..bbcbc28 100644
--- a/tests/MultiFormObjectDecoratorTest.php
+++ b/tests/MultiFormObjectDecoratorTest.php
@@ -34,7 +34,6 @@ class MultiFormObjectDecoratorTest extends SapphireTest
             ->filter(['MultiFormIsTemporary' => 1])
             ->map('Name')
             ->toArray();
-
         $this->assertNotContains('Test 1', $records);
         $this->assertNotContains('Test 2', $records);
         $this->assertContains('Test 3', $records);
diff --git a/tests/MultiFormTest.php b/tests/MultiFormTest.php
index d0e9169..50b2476 100644
--- a/tests/MultiFormTest.php
+++ b/tests/MultiFormTest.php
@@ -30,7 +30,7 @@ use SilverStripe\MultiForm\Models\MultiFormSession;
  */
 class MultiFormTest extends FunctionalTest
 {
-    public static $fixture_file = 'MultiFormTest.yml';
+    protected static $fixture_file = 'MultiFormTest.yml';
 
     /**
      * @var MultiFormTestController
@@ -120,7 +120,11 @@ class MultiFormTest extends FunctionalTest
         Config::modify()->set(MultiForm::class, 'get_var', 'SuperSessionID');
 
         $form = $this->controller->Form();
-        $this->assertContains('SuperSessionID', $form::$ignored_fields, "GET var wasn't added to ignored fields");
+        $this->assertContains(
+            'SuperSessionID',
+            $form->config()->get('ignored_fields'),
+            'GET var wasn\'t added to ignored fields'
+        );
         $this->assertContains(
             'SuperSessionID',
             $form->FormAction(),
diff --git a/tests/Stubs/MultiFormStepOne.php b/tests/Stubs/MultiFormStepOne.php
index fdc87b8..1511ce1 100644
--- a/tests/Stubs/MultiFormStepOne.php
+++ b/tests/Stubs/MultiFormStepOne.php
@@ -14,7 +14,7 @@ use SilverStripe\MultiForm\Models\MultiFormStep;
  */
 class MultiFormTestStepOne extends MultiFormStep implements TestOnly
 {
-    public static $next_steps = MultiFormTestStepTwo::class;
+    private static $next_steps = MultiFormTestStepTwo::class;
 
     public function getFields()
     {
diff --git a/tests/Stubs/MultiFormTestForm.php b/tests/Stubs/MultiFormTestForm.php
index aeb5ab5..ca569e2 100644
--- a/tests/Stubs/MultiFormTestForm.php
+++ b/tests/Stubs/MultiFormTestForm.php
@@ -11,10 +11,10 @@ use SilverStripe\MultiForm\Models\MultiForm;
  */
 class MultiFormTestForm extends MultiForm implements TestOnly
 {
-    public static $start_step = MultiFormTestStepOne::class;
+    private static $start_step = MultiFormTestStepOne::class;
 
     public function getStartStep()
     {
-        return self::$start_step;
+        return $this->config()->get('start_step');
     }
 }
diff --git a/tests/Stubs/MultiFormTestStepThree.php b/tests/Stubs/MultiFormTestStepThree.php
index a677c14..1644456 100644
--- a/tests/Stubs/MultiFormTestStepThree.php
+++ b/tests/Stubs/MultiFormTestStepThree.php
@@ -13,7 +13,7 @@ use SilverStripe\MultiForm\Models\MultiFormStep;
  */
 class MultiFormTestStepThree extends MultiFormStep implements TestOnly
 {
-    public static $is_final_step = true;
+    private static $is_final_step = true;
 
     public function getFields()
     {
diff --git a/tests/Stubs/MultiFormTestStepTwo.php b/tests/Stubs/MultiFormTestStepTwo.php
index 2ad20d5..e1abf6a 100644
--- a/tests/Stubs/MultiFormTestStepTwo.php
+++ b/tests/Stubs/MultiFormTestStepTwo.php
@@ -12,7 +12,7 @@ use SilverStripe\MultiForm\Models\MultiFormStep;
  */
 class MultiFormTestStepTwo extends MultiFormStep implements TestOnly
 {
-    public static $next_steps = MultiFormTestStepThree::class;
+    private static $next_steps = MultiFormTestStepThree::class;
 
     public function getFields()
     {