diff --git a/tests/Socialbox/AddressBookTest.php b/tests/Socialbox/AddressBookTest.php
index 4376b60..89b4667 100644
--- a/tests/Socialbox/AddressBookTest.php
+++ b/tests/Socialbox/AddressBookTest.php
@@ -43,6 +43,24 @@
             $this->assertTrue($aliceClient->addressBookContactExists($johnClient->getIdentifiedAs()));
         }
 
+        /**
+         * @throws RpcException
+         * @throws ResolutionException
+         * @throws CryptographyException
+         * @throws DatabaseOperationException
+         */
+        public function testAddressBookAddInvalidAddress(): void
+        {
+            $johnClient = Helper::generateRandomClient(TEAPOT_DOMAIN, prefix: 'johnAddressBookTest');
+            $johnClient->settingsAddInformationField(InformationFieldName::DISPLAY_NAME, 'John Doe');
+            $johnClient->settingsSetPassword('SecretTestingPassword123');
+            $this->assertTrue($johnClient->getSessionState()->isAuthenticated());
+
+            $this->expectException(RpcException::class);
+            $this->expectExceptionCode(StandardError::RPC_INVALID_ARGUMENTS->value);
+            $johnClient->addressBookAddContact('invalid invalid invalid');
+        }
+
         /**
          * @throws ResolutionException
          * @throws RpcException
@@ -617,6 +635,23 @@
             $this->assertFalse($johnClient->addressBookDeleteContact(Helper::generateRandomPeer($johnClient->getIdentifiedAs()->getDomain())));
         }
 
+        /**
+         * @throws RpcException
+         * @throws ResolutionException
+         * @throws CryptographyException
+         * @throws DatabaseOperationException
+         */
+        public function testDeleteInvalidContact(): void
+        {
+            $johnClient = Helper::generateRandomClient(TEAPOT_DOMAIN, prefix: 'johnAddressBookTest');
+            $this->assertTrue($johnClient->settingsAddInformationField(InformationFieldName::DISPLAY_NAME, 'John Doe', PrivacyState::PUBLIC));
+            $this->assertTrue($johnClient->settingsSetPassword('SecretTestingPassword123'));
+
+            $this->expectException(RpcException::class);
+            $this->expectExceptionCode(StandardError::RPC_INVALID_ARGUMENTS->value);
+            $this->assertFalse($johnClient->addressBookDeleteContact('invalid invalid invalid'));
+        }
+
         /**
          * @throws DatabaseOperationException
          * @throws ResolutionException