diff --git a/src/Socialbox/Classes/StandardMethods/AddressBook/AddressBookUpdateRelationship.php b/src/Socialbox/Classes/StandardMethods/AddressBook/AddressBookUpdateRelationship.php
index b170085..45dce14 100644
--- a/src/Socialbox/Classes/StandardMethods/AddressBook/AddressBookUpdateRelationship.php
+++ b/src/Socialbox/Classes/StandardMethods/AddressBook/AddressBookUpdateRelationship.php
@@ -30,7 +30,7 @@
 
             try
             {
-                $address = PeerAddress::fromAddress($rpcRequest->getParameter('peer'));
+                $receivingPeerAddress = PeerAddress::fromAddress($rpcRequest->getParameter('peer'));
             }
             catch(InvalidArgumentException $e)
             {
@@ -41,8 +41,8 @@
             {
                 throw new MissingRpcArgumentException('relationship');
             }
-            $relationship = ContactRelationshipType::tryFrom(strtoupper($rpcRequest->getParameter('relationship')));
-            if($relationship === null)
+            $newRelationship = ContactRelationshipType::tryFrom(strtoupper($rpcRequest->getParameter('relationship')));
+            if($newRelationship === null)
             {
                 throw new InvalidRpcArgumentException('relationship');
             }
@@ -50,14 +50,14 @@
             try
             {
                 // Check if the contact already exists
-                $peer = $request->getPeer();
-                if(!ContactManager::isContact($peer, $address))
+                $requestingPeer = $request->getPeer();
+                if(!ContactManager::isContact($requestingPeer->getUuid(), $receivingPeerAddress))
                 {
                     return $rpcRequest->produceError(StandardError::FORBIDDEN, 'Contact does not exist');
                 }
 
                 // Create the contact
-                ContactManager::updateContactRelationship($peer, $address, $relationship);
+                ContactManager::updateContactRelationship($requestingPeer->getUuid(), $receivingPeerAddress, $newRelationship);
             }
             catch (DatabaseOperationException $e)
             {
diff --git a/src/Socialbox/Managers/ContactManager.php b/src/Socialbox/Managers/ContactManager.php
index 29941f9..e220249 100644
--- a/src/Socialbox/Managers/ContactManager.php
+++ b/src/Socialbox/Managers/ContactManager.php
@@ -2,10 +2,13 @@
 
     namespace Socialbox\Managers;
 
+    use DateTime;
+    use InvalidArgumentException;
     use ncc\ThirdParty\Symfony\Uid\UuidV4;
     use PDO;
     use PDOException;
     use Socialbox\Classes\Database;
+    use Socialbox\Classes\Validator;
     use Socialbox\Enums\Types\ContactRelationshipType;
     use Socialbox\Exceptions\DatabaseOperationException;
     use Socialbox\Objects\Database\ContactDatabaseRecord;
@@ -30,6 +33,15 @@
             {
                 $contactAddress = $contactAddress->getAddress();
             }
+            elseif(!Validator::validateUuid($contactAddress))
+            {
+                throw new InvalidArgumentException('The given contact address is invalid');
+            }
+
+            if(!Validator::validateUuid($peerUuid))
+            {
+                throw new InvalidArgumentException('The given peer internal UUID is not a valid UUID V4');
+            }
 
             try
             {
@@ -188,6 +200,15 @@
             {
                 $contactAddress = $contactAddress->getAddress();
             }
+            elseif(!Validator::validatePeerAddress($contactAddress))
+            {
+                throw new InvalidArgumentException('The given contact address is not a valid peer address');
+            }
+
+            if(!Validator::validateUuid($peerUuid))
+            {
+                throw new InvalidArgumentException('The given internal peer UUID is not a valid UUID V4');
+            }
 
             try
             {
@@ -360,7 +381,7 @@
                 $statement->bindParam(':expires', $expires);
                 $created = $signingKey->getCreated();
                 $statement->bindParam(':created', $created);
-                $trustedOn = (new \DateTime())->format('Y-m-d H:i:s');
+                $trustedOn = (new DateTime())->format('Y-m-d H:i:s');
                 $statement->bindParam(':trusted_on', $trustedOn);
             }
             catch(PDOException $e)