diff --git a/lib/AdminPages/Pages/Forms.php b/lib/AdminPages/Pages/Forms.php
index 19a9966810..c2a653c649 100644
--- a/lib/AdminPages/Pages/Forms.php
+++ b/lib/AdminPages/Pages/Forms.php
@@ -65,7 +65,7 @@ class Forms {
       $data['premium_plugin_active'] = License::getLicense();
       $data['current_wp_user_firstname'] = $this->wp->wpGetCurrentUser()->user_firstname;
       $installedAtDiff = (new \DateTime($this->settings->get('installed_at')))->diff(new \DateTime());
-      $data['installed_days_ago'] = $installedAtDiff instanceof \DateInterval ? (int)$installedAtDiff->format('%a') : null;
+      $data['installed_days_ago'] = (int)$installedAtDiff->format('%a');
       $data['display_nps_survey'] = true;
       $this->userFlags->set('display_new_form_editor_nps_survey', false);
     }
diff --git a/lib/AdminPages/Pages/Newsletters.php b/lib/AdminPages/Pages/Newsletters.php
index 76fd0c0c86..5ac92f9284 100644
--- a/lib/AdminPages/Pages/Newsletters.php
+++ b/lib/AdminPages/Pages/Newsletters.php
@@ -134,7 +134,7 @@ class Newsletters {
     $data['roles']['mailpoet_all'] = $this->wp->__('In any WordPress role', 'mailpoet');
 
     $installedAtDiff = (new \DateTime($this->settings->get('installed_at')))->diff(new \DateTime());
-    $data['installed_days_ago'] = $installedAtDiff instanceof \DateInterval ? (int)$installedAtDiff->format('%a') : null;
+    $data['installed_days_ago'] = (int)$installedAtDiff->format('%a');
 
     $data['subscribers_limit'] = $this->subscribersFeature->getSubscribersLimit();
     $data['subscribers_limit_reached'] = $this->subscribersFeature->check();
diff --git a/lib/Doctrine/Driver/PDOConnection.php b/lib/Doctrine/Driver/PDOConnection.php
index 0c8ad5e3c5..deab5b6b48 100644
--- a/lib/Doctrine/Driver/PDOConnection.php
+++ b/lib/Doctrine/Driver/PDOConnection.php
@@ -3,7 +3,6 @@
 namespace MailPoet\Doctrine\Driver;
 
 use MailPoet\InvalidStateException;
-use MailPoet\RuntimeException;
 
 class PDOConnection implements \MailPoetVendor\Doctrine\DBAL\Driver\Connection, \MailPoetVendor\Doctrine\DBAL\Driver\ServerInfoAwareConnection {
   /** @var \PDO */
@@ -51,9 +50,6 @@ class PDOConnection implements \MailPoetVendor\Doctrine\DBAL\Driver\Connection,
   public function prepare($prepareString, $driverOptions = []) {
     try {
       $preparedStatement = $this->connection->prepare($prepareString, $driverOptions);
-      if ($preparedStatement === false) {
-        throw new RuntimeException('Unable to prepare PDOStatement.');
-      }
       return $this->createStatement($preparedStatement);
     } catch (\PDOException $exception) {
       throw new \MailPoetVendor\Doctrine\DBAL\Driver\PDOException($exception);
@@ -99,14 +95,9 @@ class PDOConnection implements \MailPoetVendor\Doctrine\DBAL\Driver\Connection,
   public function lastInsertId($name = null) {
     try {
       if ($name === null) {
-        $lastId = $this->connection->lastInsertId();
-      } else {
-        $lastId = $this->connection->lastInsertId($name);
+        return $this->connection->lastInsertId();
       }
-      if ($lastId === false) {
-        return '';
-      }
-      return $lastId;
+      return $this->connection->lastInsertId($name);
     } catch (\PDOException $exception) {
       throw new \MailPoetVendor\Doctrine\DBAL\Driver\PDOException($exception);
     }
diff --git a/tasks/phpstan/php-version-dependent-config-libs.php b/tasks/phpstan/php-version-dependent-config-libs.php
index f3b514fbb1..7bad77c75d 100644
--- a/tasks/phpstan/php-version-dependent-config-libs.php
+++ b/tasks/phpstan/php-version-dependent-config-libs.php
@@ -8,26 +8,6 @@ $config['parameters']['phpVersion'] = $phpVersion;
 # PHPStan gets smarter when runs on PHP8 and some type checks added because of PHP8 are reported as unnecessary when we run PHPStan on PHP7
 # see https://github.com/phpstan/phpstan/issues/4060
 if ($phpVersion < 80000) {
-  $config['parameters']['ignoreErrors'][] = [
-    'message' => '#^Else branch is unreachable because ternary operator condition is always true#',
-    'path' => __DIR__ . '/../../lib/AdminPages/Pages/Forms.php',
-    'count' => 1,
-  ];
-  $config['parameters']['ignoreErrors'][] = [
-    'message' => '#^Else branch is unreachable because ternary operator condition is always true#',
-    'path' => __DIR__ . '/../../lib/AdminPages/Pages/Newsletters.php',
-    'count' => 1,
-  ];
-  $config['parameters']['ignoreErrors'][] = [
-    'message' => '#^Strict comparison using === between PDOStatement and false will always evaluate to false#',
-    'path' => __DIR__ . '/../../lib/Doctrine/Driver/PDOConnection.php',
-    'count' => 1,
-  ];
-  $config['parameters']['ignoreErrors'][] = [
-    'message' => '#^Strict comparison using === between string and false will always evaluate to false#',
-    'path' => __DIR__ . '/../../lib/Doctrine/Driver/PDOConnection.php',
-    'count' => 1,
-  ];
   $config['parameters']['ignoreErrors'][] = [
     'message' => '#^Cannot access offset \\(int\\|string\\) on array\\|false#',
     'path' => __DIR__ . '/../../lib/Features/FeatureFlagsController.php',