diff --git a/src/PageTypes/DatedUpdateHolder.php b/src/PageTypes/DatedUpdateHolder.php
index 2751752..4f36861 100644
--- a/src/PageTypes/DatedUpdateHolder.php
+++ b/src/PageTypes/DatedUpdateHolder.php
@@ -152,7 +152,7 @@ public static function AllUpdates(
             // Try running query inside try/catch block to handle any invalid date format
             $items->dataQuery()->execute();
         } catch (DatabaseException $e) {
-            self::handleInvalidDateFormat($e);
+            DatedUpdateHolder::handleInvalidDateFormat($e);
             // Ensure invalid SQL does not get run again
             $items = $className::get()->limit(null);
         }
@@ -213,7 +213,7 @@ public static function ExtractMonths(
                 ])
                 ->execute();
         } catch (DatabaseException $e) {
-            self::handleInvalidDateFormat($e);
+            DatedUpdateHolder::handleInvalidDateFormat($e);
         }
 
         $years = [];
diff --git a/src/PageTypes/DatedUpdateHolderController.php b/src/PageTypes/DatedUpdateHolderController.php
index d721ffa..bf7be69 100644
--- a/src/PageTypes/DatedUpdateHolderController.php
+++ b/src/PageTypes/DatedUpdateHolderController.php
@@ -177,7 +177,7 @@ public function parseParams($produceErrorMessages = true)
             }
         } catch (InvalidArgumentException $e) {
             if ($produceErrorMessages) {
-                $this->getRequest()->getSession()->set(self::TEMP_FORM_MESSAGE, _t(
+                $this->getRequest()->getSession()->set(DatedUpdateHolderController::TEMP_FORM_MESSAGE, _t(
                     __CLASS__ . '.InvalidDateFormat',
                     'Dates must be in "y-MM-dd" format.'
                 ));
@@ -200,7 +200,7 @@ public function parseParams($produceErrorMessages = true)
             list($to, $from) = [$from, $to];
 
             if ($produceErrorMessages) {
-                $this->getRequest()->getSession()->set(self::TEMP_FORM_MESSAGE, _t(
+                $this->getRequest()->getSession()->set(DatedUpdateHolderController::TEMP_FORM_MESSAGE, _t(
                     __CLASS__ . '.FilterAppliedMessage',
                     'Filter has been applied with the dates reversed.'
                 ));
@@ -210,7 +210,7 @@ public function parseParams($produceErrorMessages = true)
         // Notify the user that filtering by single date is taking place.
         if (isset($from) && !isset($to)) {
             if ($produceErrorMessages) {
-                $this->getRequest()->getSession()->set(self::TEMP_FORM_MESSAGE, _t(
+                $this->getRequest()->getSession()->set(DatedUpdateHolderController::TEMP_FORM_MESSAGE, _t(
                     __CLASS__ . '.DateRangeFilterMessage',
                     'Filtered by a single date.'
                 ));
@@ -347,9 +347,9 @@ public function DateRangeForm()
         $form->setFormMethod('get');
 
         // Add any locally stored form messages before returning
-        if ($formMessage = $this->getRequest()->getSession()->get(self::TEMP_FORM_MESSAGE)) {
+        if ($formMessage = $this->getRequest()->getSession()->get(DatedUpdateHolderController::TEMP_FORM_MESSAGE)) {
             $form->setMessage($formMessage, ValidationResult::TYPE_WARNING);
-            $this->getRequest()->getSession()->clear(self::TEMP_FORM_MESSAGE);
+            $this->getRequest()->getSession()->clear(DatedUpdateHolderController::TEMP_FORM_MESSAGE);
         }
 
         return $form;