diff --git a/lib/Service/RecoveryEmailService.php b/lib/Service/RecoveryEmailService.php
index 4266d56baf78908689d2f902fcf3e69b2e3c0c3f..101d174d1268d3bb4ed854ffe64287360e1c5d11 100644
--- a/lib/Service/RecoveryEmailService.php
+++ b/lib/Service/RecoveryEmailService.php
@@ -268,12 +268,12 @@ class RecoveryEmailService {
 				$responseBody = $response->getBody(); // Get the response body as a string
 				$data = json_decode($responseBody, true);
 				
-				if ($data['disposable'] ?? false) {
+				if (isset($data['disposable']) && $data['disposable'] === true) {
 					$this->logger->info("User ID $username's requested recovery email address is disposable.");
 					throw new BlacklistedEmailException($l->t('The email address is disposable. Please provide another recovery address.'));
 				}
 	
-				if (!$data['deliverable_email'] ?? true) {
+				if (isset($data['deliverable_email']) && $data['deliverable_email'] === false) {
 					$this->logger->info("User ID $username's requested recovery email address is not deliverable.");
 					throw new BlacklistedEmailException($l->t('The email address is not deliverable. Please provide another recovery address.'));
 				}
@@ -310,13 +310,13 @@ class RecoveryEmailService {
 			}
 	
 			// Handle response data
-			if ($data['disposable'] ?? false) {
+			if (isset($data['disposable']) && $data['disposable'] === true) {
 				$this->logger->info("User ID $username's requested recovery email address is from a disposable domain.");
 				$this->domainService->addCustomDisposableDomain($domain, $l, $data['related_domains'] ?? []);
 				throw new BlacklistedEmailException($l->t('The email address is disposable. Please provide another recovery address.'));
 			}
-	
-			if (!$data['mx'] ?? true) {
+
+			if (isset($data['mx']) && $data['mx'] === false) {
 				$this->logger->info("User ID $username's requested recovery email address domain is not valid.");
 				$this->domainService->addCustomDisposableDomain($domain, $l, $data['related_domains'] ?? []);
 				throw new BlacklistedEmailException($l->t('The email address is not deliverable. Please provide another recovery address.'));